- 24 Aug, 2016 3 commits
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Maarten Lankhorst authored
Instead of iterating overthe connectors manually, run the last part of DDI disabling inside the crt post disable function. This was meant to be addressed before submitting the other commit, but I missed the review comments. Fixes: fd6bbda9 ("drm/i915: Pass crtc_state and connector_state to encoder functions") Signed-off-by:
Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1471961888-10771-2-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by:
Daniel Vetter <daniel.vetter@ffwll.ch> [mlankhorst: Fix extra whitespace between functions.]
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Maarten Lankhorst authored
This makes the code in intel_sanitize_encoder slightly more readable. This was meant to be addressed in fd6bbda9, but I missed that review comment. Fixes: fd6bbda9 ("drm/i915: Pass crtc_state and connector_state to encoder functions") Signed-off-by:
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Daniel Vetter authored
Somehow architectures can't agree on this. And for good measure make sure we have a fallback which should work everywhere (fingers crossed). v2: Make it compile properly, needs a defined() for the #elif. Fixes: ac96b556 ("io-mapping.h: s/PAGE_KERNEL_IO/PAGE_KERNEL/") Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: linux-mm@kvack.org Reviewed-by:
Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:
Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by:
Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20160823202233.4681-1-daniel.vetter@ffwll.ch
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- 23 Aug, 2016 17 commits
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Chris Wilson authored
PAGE_KERNEL_IO is an x86-ism. Though it is used to define the pgprot_t used for the iomapped region, it itself is just PAGE_KERNEL. On all other arches, PAGE_KERNEL_IO is undefined so in a general header we must refrain from using it. v2: include pgtable for pgprot_combine() Reported-by:
Stephen Rothwell <sfr@canb.auug.org.au> Fixes: cafaf14a ("io-mapping: Always create a struct to hold metadata about the io-mapping") Signed-off-by:
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Lyude authored
Thanks to Ville for suggesting this as a potential solution to pipe underruns on Skylake. On Skylake all of the registers for configuring planes, including the registers for configuring their watermarks, are double buffered. New values written to them won't take effect until said registers are "armed", which is done by writing to the PLANE_SURF (or in the case of cursor planes, the CURBASE register) register. With this in mind, up until now we've been updating watermarks on skl like this: non-modeset { - calculate (during atomic check phase) - finish_atomic_commit: - intel_pre_plane_update: - intel_update_watermarks() - {vblank happens; new watermarks + old plane values => underrun } - drm_atomic_helper_commit_planes_on_crtc: - start vblank evasion - write new plane registers - end vblank evasion } or modeset { - calculate (during atomic check phase) - finish_atomic_commit: - crtc_enable: - intel_update_watermarks() - {vblank happens; new watermarks + old plane values => underrun } - drm_atomic_helper_commit_planes_on_crtc: - start vblank evasion - write new plane registers - end vblank evasion } Now we update watermarks atomically like this: non-modeset { - calculate (during atomic check phase) - finish_atomic_commit: - intel_pre_plane_update: - intel_update_watermarks() (wm values aren't written yet) - drm_atomic_helper_commit_planes_on_crtc: - start vblank evasion - write new plane registers - write new wm values - end vblank evasion } modeset { - calculate (during atomic check phase) - finish_atomic_commit: - crtc_enable: - intel_update_watermarks() (actual wm values aren't written yet) - drm_atomic_helper_commit_planes_on_crtc: - start vblank evasion - write new plane registers - write new wm values - end vblank evasion } So this patch moves all of the watermark writes into the right place; inside of the vblank evasion where we update all of the registers for each plane. While this patch doesn't fix everything, it does allow us to update the watermark values in the way the hardware expects us to. Changes since original patch series: - Remove mutex_lock/mutex_unlock since they don't do anything and we're not touching global state - Move skl_write_cursor_wm/skl_write_plane_wm functions into intel_pm.c, make externally visible - Add skl_write_plane_wm calls to skl_update_plane - Fix conditional for for loop in skl_write_plane_wm (level < max_level should be level <= max_level) - Make diagram in commit more accurate to what's actually happening - Add Fixes: Changes since v1: - Use IS_GEN9() instead of IS_SKYLAKE() since these fixes apply to more then just Skylake - Update description to make it clear this patch doesn't fix everything - Check if pipes were actually changed before writing watermarks Changes since v2: - Write PIPE_WM_LINETIME during vblank evasion Changes since v3: - Rebase against new SAGV patch changes Changes since v4: - Add a parameter to choose what skl_wm_values struct to use when writing new plane watermarks Changes since v5: - Remove cursor ddb entry write in skl_write_cursor_wm(), defer until patch 6 - Write WM_LINETIME in intel_begin_crtc_commit() Changes since v6: - Remove redundant dirty_pipes check in skl_write_plane_wm (we check this in all places where we call this function, and it was supposed to have been removed earlier anyway) - In i9xx_update_cursor(), use dev_priv->info.gen >= 9 instead of IS_GEN9(dev_priv). We do this everywhere else and I'd imagine this needs to be done for gen10 as well Changes since v7: - Fix rebase fail (unused variable obj) - Make struct skl_wm_values *wm const - Fix indenting - Use INTEL_GEN() instead of dev_priv->info.gen Changes since v8: - Don't forget calls to skl_write_plane_wm() when disabling planes - Use INTEL_GEN(), not INTEL_INFO()->gen in intel_begin_crtc_commit() Fixes: 2d41c0b5 ("drm/i915/skl: SKL Watermark Computation") Signed-off-by:Lyude <cpaul@redhat.com> Reviewed-by:
Matt Roper <matthew.d.roper@intel.com> Cc: stable@vger.kernel.org Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com> Cc: Hans de Goede <hdegoede@redhat.com> Signed-off-by:
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Maarten Lankhorst authored
crtc_state is already passed around, use it instead of crtc->config. Signed-off-by:
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Maarten Lankhorst authored
Slightly less straightforward. Some of the drrs calls are done from workers or from intel_ddi.c, pass along crtc_state when we can, or crtc->config when we can't. Signed-off-by:
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Maarten Lankhorst authored
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Maarten Lankhorst authored
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Maarten Lankhorst authored
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Maarten Lankhorst authored
Now that conn_state is passed in as argument to compute_config, it's guaranteed that there is a connector for the argument. The code that looks for the connector is now dead, and completely unused. Delete it. Signed-off-by:
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Maarten Lankhorst authored
Some places iterate over connector_state to find the right connector, pass it along as argument. Signed-off-by:
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Maarten Lankhorst authored
This is mostly code churn, with exception of a few places: - intel_display.c has changes in intel_sanitize_encoder - intel_ddi.c has intel_ddi_fdi_disable calling intel_ddi_post_disable, and required a function change. Also affects intel_display.c - intel_dp_mst.c passes a NULL crtc_state and conn_state to intel_ddi_post_disable for shutting down the real encoder. If we would pass conn_state, then conn_state->connector != intel_dig_port->connector and conn_state->best_encoder != to_intel_encoder(intel_dig_port). We also shouldn't pass crtc_state, because in that case the disabling sequence may potentially be different depending on which crtc is disabled last. Nice way to introduce bugs. No other functional changes are done, diff stat is already huge. Each encoder type will need to be fixed to use the atomic states separately. Signed-off-by:
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Maarten Lankhorst authored
This cleans up another possible use of the connector list, encoder->crtc is legacy state and should not be used. With the atomic state as argument it's easy to find the encoder from the connector it belongs to. intel_opregion_notify_encoder is a noop for !HAS_DDI, so it's harmless to unconditionally include it in encoder enable/disable. Signed-off-by:
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Maarten Lankhorst authored
This is required for supporting nonblocking modesets. Iterating over the connector list will no longer be allowed when we don't hold connection_mutex, so we have to use the atomic state. Fix disable_noatomic by populating the minimal state required to disable a connector. Signed-off-by:
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Maarten Lankhorst authored
No idea if it supports it, but this is the minimum required from get_dpll. Signed-off-by:
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- 22 Aug, 2016 20 commits
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Chris Wilson authored
As we do many register reads within a very short period of time, hold the GMBUS powerwell from start to finish. Signed-off-by:
David Weinehall <david.weinehall@linux.intel.com>
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Chris Wilson authored
An unlikely ABBA deadlock in debugfs that no one has reported. [ 284.922349] ====================================================== [ 284.922355] [ INFO: possible circular locking dependency detected ] [ 284.922361] 4.8.0-rc2+ #430 Tainted: G W [ 284.922366] ------------------------------------------------------- [ 284.922371] cat/1197 is trying to acquire lock: [ 284.922376] (&dev->filelist_mutex){+.+...}, at: [<ffffffffa0055ba2>] i915_ppgtt_info+0x82/0x390 [i915] [ 284.922423] [ 284.922423] but task is already holding lock: [ 284.922429] (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0055b55>] i915_ppgtt_info+0x35/0x390 [i915] [ 284.922465] [ 284.922465] which lock already depends on the new lock. [ 284.922465] [ 284.922471] [ 284.922471] the existing dependency chain (in reverse order) is: [ 284.922477] -> #1 (&dev->struct_mutex){+.+.+.}: [ 284.922493] [<ffffffff81087710>] lock_acquire+0x60/0x80 [ 284.922505] [<ffffffff8143e96f>] mutex_lock_nested+0x5f/0x360 [ 284.922520] [<ffffffffa004f877>] print_context_stats+0x37/0xf0 [i915] [ 284.922549] [<ffffffffa00535f5>] i915_gem_object_info+0x265/0x490 [i915] [ 284.922581] [<ffffffff81144491>] seq_read+0xe1/0x3b0 [ 284.922592] [<ffffffff811f77b3>] full_proxy_read+0x83/0xb0 [ 284.922604] [<ffffffff8111ba03>] __vfs_read+0x23/0x110 [ 284.922616] [<ffffffff8111c9b9>] vfs_read+0x89/0x110 [ 284.922626] [<ffffffff8111dbf4>] SyS_read+0x44/0xa0 [ 284.922636] [<ffffffff81442be9>] entry_SYSCALL_64_fastpath+0x1c/0xac [ 284.922648] -> #0 (&dev->filelist_mutex){+.+...}: [ 284.922667] [<ffffffff810871fc>] __lock_acquire+0x10fc/0x1270 [ 284.922678] [<ffffffff81087710>] lock_acquire+0x60/0x80 [ 284.922689] [<ffffffff8143e96f>] mutex_lock_nested+0x5f/0x360 [ 284.922701] [<ffffffffa0055ba2>] i915_ppgtt_info+0x82/0x390 [i915] [ 284.922729] [<ffffffff81144491>] seq_read+0xe1/0x3b0 [ 284.922739] [<ffffffff811f77b3>] full_proxy_read+0x83/0xb0 [ 284.922750] [<ffffffff8111ba03>] __vfs_read+0x23/0x110 [ 284.922761] [<ffffffff8111c9b9>] vfs_read+0x89/0x110 [ 284.922771] [<ffffffff8111dbf4>] SyS_read+0x44/0xa0 [ 284.922781] [<ffffffff81442be9>] entry_SYSCALL_64_fastpath+0x1c/0xac [ 284.922793] [ 284.922793] other info that might help us debug this: [ 284.922793] [ 284.922809] Possible unsafe locking scenario: [ 284.922809] [ 284.922818] CPU0 CPU1 [ 284.922825] ---- ---- [ 284.922831] lock(&dev->struct_mutex); [ 284.922842] lock(&dev->filelist_mutex); [ 284.922854] lock(&dev->struct_mutex); [ 284.922865] lock(&dev->filelist_mutex); [ 284.922875] [ 284.922875] *** DEADLOCK *** [ 284.922875] [ 284.922888] 3 locks held by cat/1197: [ 284.922895] #0: (debugfs_srcu){......}, at: [<ffffffff811f7730>] full_proxy_read+0x0/0xb0 [ 284.922919] #1: (&p->lock){+.+.+.}, at: [<ffffffff811443e8>] seq_read+0x38/0x3b0 [ 284.922942] #2: (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0055b55>] i915_ppgtt_info+0x35/0x390 [i915] [ 284.922983] Fixes: 1d2ac403 ("drm: Protect dev->filelist with its own mutex") Signed-off-by: -
Chris Wilson authored
If the engine isn't being retired (worker starvation?) then it is possible for us to repeatedly observe that between consecutive hangchecks the seqno on the ring to be the same and there remain unretired requests. Ignore these completely and only regard the engine as busy for the purpose of hang detection (not stall detection) if there are outstanding breadcrumbs. In recent history we have looked at using both the request and seqno as indication of activity on the engine, but that was reduced to just inspecting seqno in commit cffa781e ("drm/i915: Simplify check for idleness in hangcheck"). However, in commit dcff85c8 ("drm/i915: Enable i915_gem_wait_for_idle() without holding struct_mutex"), I made the decision to use the new common lockless function, under the assumption that request retirement was more frequent than hangcheck and so we would not have a stuck busy check. The flaw there was in forgetting that we accumulate the hang score, and so successive checks seeing a stuck request, albeit with the GPU advancing elsewhere and so not necessary the same stuck request, would eventually trigger the hang. Fixes: dcff85c8 ("drm/i915: Enable i915_gem_wait_for_idle()...") Signed-off-by:
Mika Kuoppala <mika.kuoppala@intel.com>
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Chris Wilson authored
As we never need to directly access the pages we allocate for scratch and the pagetables, and always remap them into the GTT through the dma remapper, we do not need to limit the allocations to lowmem i.e. we can pass in the __GFP_HIGHMEM flag to the page allocation. For backwards compatibility, e.g. certain old GPUs not liking highmem for certain functions that may be accidentally mapped to the scratch page by userspace, keep the GMCH probe as only allocating from DMA32. Signed-off-by:
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Chris Wilson authored
As the scratch page is no longer shared between all VM, and each has their own, forgo the small allocation and simply embed the scratch page struct into the i915_address_space. Signed-off-by:
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David Weinehall authored
Just like with sysfs, we do some major overhaul. Pass dev_priv instead of dev to all feature macros (IS_, HAS_, INTEL_, etc.). This has the side effect that a bunch of functions now get dev_priv passed instead of dev. All calls to INTEL_INFO()->gen have been replaced with INTEL_GEN(). We want access to to_i915(node->minor->dev) in a lot of places, so add the node_to_i915() helper to accommodate for this. Finally, we have quite a few cases where we get a void * pointer, and need to cast it to drm_device *, only to run to_i915() on it. Add cast_to_i915() to do this. v2: Don't introduce extra dev (Chris) v3: Make pipe_crc_info have a pointer to drm_i915_private instead of drm_device. This saves a bit of space, since we never use drm_device anywhere in these functions. Also some minor fixup that I missed in the previous version. v4: Changed the code a bit so that dev_priv is passed directly to various functions, thus removing the need for the cast_to_i915() helper. Also did some additional cleanup. v5: Additional cleanup of newly introduced changes. v6: Rebase again because of conflict. Signed-off-by: -
David Weinehall authored
In an effort to simplify things for a future push of dev_priv instead of dev wherever possible, always take pdev via dev_priv where feasible, eliminating the direct access from dev. Right now this only eliminates a few cases of dev, but it also obviates that we pass dev into a lot of functions where dev_priv would be the more obvious choice. v2: Fixed one more place missing in the previous patch set Signed-off-by:
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David Weinehall authored
Various cleanup for i915_sysfs.c; we now use dev_priv whenever possible. The kdev_to_drm_minor() helper function has been replaced by one that converts from struct device * to struct drm_i915_private *. We already have a seemingly identical helper (kdev_to_i915()) in i915_drv.h. But that one cannot be used here. Unlike the version in i915_drv.h, this helper reaches i915 through drm_minor. v2: Rename kdev_to_i915_dm() to kdev_minor_to_i915() (Chris) Signed-off-by:
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David Weinehall authored
We currently have a mix of struct device *device, struct device *kdev, and struct device *dev (the latter forcing us to refer to struct drm_device as something else than the normal dev). To simplify things, always use kdev when referring to struct device. v2: Replace the dev_to_drm_minor() macro with the inline function kdev_to_drm_minor(). Signed-off-by: -
David Weinehall authored
Fix minor whitespace issues plus a typo. Signed-off-by:
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Maarten Lankhorst authored
Merge commit 5e580523 reverts the version bumping parts of commit 4aa7fb9c. Bump the versions again and request the specific firmware version. The currently recommended versions are: SKL 1.26, KBL 1.01 and BXT 1.07. Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com> Cc: Imre Deak <imre.deak@intel.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97242 Cc: drm-intel-fixes@lists.freedesktop.org Fixes: 5e580523 ("Backmerge tag 'v4.7' into drm-next") Signed-off-by:
Imre Deak <imre.deak@intel.com>
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Lyude authored
If we're enabling a pipe, we'll need to modify the watermarks on all active planes. Since those planes won't be added to the state on their own, we need to add them ourselves. Signed-off-by:
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Matt Roper authored
When we write watermark values to the hardware, those values are stored in dev_priv->wm.skl_hw. However with recent watermark changes, the results structure we're copying from only contains valid watermark and DDB values for the pipes that are actually changing; the values for other pipes remain 0. Thus a blind copy of the entire skl_wm_values structure will clobber the values for unchanged pipes...we need to be more selective and only copy over the values for the changing pipes. This mistake was hidden until recently due to another bug that caused us to erroneously re-calculate watermarks for all active pipes rather than changing pipes. Only when that bug was fixed was the impact of this bug discovered (e.g., modesets failing with "Requested display configuration exceeds system watermark limitations" messages and leaving watermarks non-functional, even ones initiated by intel_fbdev_restore_mode). Changes since v1: - Add a function for copying a pipe's wm values (skl_copy_wm_for_pipe()) so we can reuse this later Fixes: 734fa01f ("drm/i915/gen9: Calculate watermarks during atomic 'check' (v2)") Fixes: 9b613022 ("drm/i915/gen9: Re-allocate DDB only for changed pipes") Signed-off-by:
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Lyude authored
Since the watermark calculations for Skylake are still broken, we're apt to hitting underruns very easily under multi-monitor configurations. While it would be lovely if this was fixed, it's not. Another problem that's been coming from this however, is the mysterious issue of underruns causing full system hangs. An easy way to reproduce this with a skylake system: - Get a laptop with a skylake GPU, and hook up two external monitors to it - Move the cursor from the built-in LCD to one of the external displays as quickly as you can - You'll get a few pipe underruns, and eventually the entire system will just freeze. After doing a lot of investigation and reading through the bspec, I found the existence of the SAGV, which is responsible for adjusting the system agent voltage and clock frequencies depending on how much power we need. According to the bspec: "The display engine access to system memory is blocked during the adjustment time. SAGV defaults to enabled. Software must use the GT-driver pcode mailbox to disable SAGV when the display engine is not able to tolerate the blocking time." The rest of the bspec goes on to explain that software can simply leave the SAGV enabled, and disable it when we use interlaced pipes/have more then one pipe active. Sure enough, with this patchset the system hangs resulting from pipe underruns on Skylake have completely vanished on my T460s. Additionally, the bspec mentions turning off the SAGV with more then one pipe enabled as a workaround for display underruns. While this patch doesn't entirely fix that, it looks like it does improve the situation a little bit so it's likely this is going to be required to make watermarks on Skylake fully functional. This will still need additional work in the future: we shouldn't be enabling the SAGV if any of the currently enabled planes can't enable WM levels that introduce latencies >= 30 µs. Changes since v11: - Add skl_can_enable_sagv() - Make sure we don't enable SAGV when not all planes can enable watermarks >= the SAGV engine block time. I was originally going to save this for later, but I recently managed to run into a machine that was having problems with a single pipe configuration + SAGV. - Make comparisons to I915_SKL_SAGV_NOT_CONTROLLED explicit - Change I915_SAGV_DYNAMIC_FREQ to I915_SAGV_ENABLE - Move printks outside of mutexes - Don't print error messages twice Changes since v10: - Apparently sandybridge_pcode_read actually writes values and reads them back, despite it's misleading function name. This means we've been doing this mostly wrong and have been writing garbage to the SAGV control. Because of this, we no longer attempt to read the SAGV status during initialization (since there are no helpers for this). - mlankhorst noticed that this patch was breaking on some very early pre-release Skylake machines, which apparently don't allow you to disable the SAGV. To prevent machines from failing tests due to SAGV errors, if the first time we try to control the SAGV results in the mailbox indicating an invalid command, we just disable future attempts to control the SAGV state by setting dev_priv->skl_sagv_status to I915_SKL_SAGV_NOT_CONTROLLED and make a note of it in dmesg. - Move mutex_unlock() a little higher in skl_enable_sagv(). This doesn't actually fix anything, but lets us release the lock a little sooner since we're finished with it. Changes since v9: - Only enable/disable sagv on Skylake Changes since v8: - Add intel_state->modeset guard to the conditional for skl_enable_sagv() Changes since v7: - Remove GEN9_SAGV_LOW_FREQ, replace with GEN9_SAGV_IS_ENABLED (that's all we use it for anyway) - Use GEN9_SAGV_IS_ENABLED instead of 0x1 for clarification - Fix a styling error that snuck past me Changes since v6: - Protect skl_enable_sagv() with intel_state->modeset conditional in intel_atomic_commit_tail() Changes since v5: - Don't use is_power_of_2. Makes things confusing - Don't use the old state to figure out whether or not to enable/disable the sagv, use the new one - Split the loop in skl_disable_sagv into it's own function - Move skl_sagv_enable/disable() calls into intel_atomic_commit_tail() Changes since v4: - Use is_power_of_2 against active_crtcs to check whether we have > 1 pipe enabled - Fix skl_sagv_get_hw_state(): (temp & 0x1) indicates disabled, 0x0 enabled - Call skl_sagv_enable/disable() from pre/post-plane updates Changes since v3: - Use time_before() to compare timeout to jiffies Changes since v2: - Really apply minor style nitpicks to patch this time Changes since v1: - Added comments about this probably being one of the requirements to fixing Skylake's watermark issues - Minor style nitpicks from Matt Roper - Disable these functions on Broxton, since it doesn't have an SAGV Signed-off-by:
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Lyude authored
In order to add proper support for the SAGV, we need to be able to know what the cause of a failure to change the SAGV through the pcode mailbox was. The reasoning for this is that some very early pre-release Skylake machines don't actually allow you to control the SAGV on them, and indicate an invalid mailbox command was sent. This also might come in handy in the future for debugging. Changes since v1: - Add functions for interpreting gen6 mailbox error codes along with gen7+ error codes, and actually interpret those codes properly - Renamed patch to reflect new behavior Signed-off-by:
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Paulo Zanoni authored
intel_fbc_pre_update() depends upon the new state being already pinned in place in the Global GTT (primarily for both fencing which wants both an offset and a fence register, if assigned). This requires the call to intel_fbc_pre_update() be after intel_pin_and_fence_fb() - but commit e8216e50 ("drm/i915/fbc: call intel_fbc_pre_update earlier during page flips") moved the code way too much up in its attempt to call it before the page flip. v2 (from Paulo): - Point the original bad commit. - Add a comment to maybe prevent further regressions. Fixes: e8216e50 ("drm/i915/fbc: call intel_fbc_pre_update earlier...") Signed-off-by:
Paulo Zanoni <paulo.r.zanoni@intel.com> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Patrik Jakobsson <patrik.jakobsson@linux.intel.com> Cc: drm-intel-fixes@lists.freedesktop.org Reviewed-by:
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Daniel Vetter authored
This issue here is (I think) purely theoretical, since a compiler would need to be especially foolish to recompute the value of i915_gem_request_completed right after it was already used. Hence the additional barrier() is also not really a restriction. But I believe this to be at least permissible, and since our rcu trickery is a beast it's worth to annotate all the corner cases. Chris proposed to instead just wrap a READ_ONCE around request->fence.seqno in i915_gem_request_completed. But that has a measurable impact on code size, and everywhere we hold a full reference to the underlying request it's also not needed. And personally I'd like to have just enough barriers and locking needed for correctness, but not more - it makes it much easier in the future to understand what's going on. Since the busy ioctl has now fully embraced it's races there's no point annotating it there too. We really only need it in active_get_rcu, since that function _must_ deliver a correct snapshot of the active fences (and not chase something else). v2: Polish the comment a bit more (Chris). Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by:
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Chris Wilson authored
Since by design, if not entirely by practice, nothing is allowed to access the scratch page we use to background fill the VM, then we do not need to ensure that it is coherent between the CPU and GPU. set_pages_uc() does a stop_machine() after changing the PAT, and that significantly impacts upon context creation throughput. Signed-off-by:
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Chris Wilson authored
The passed in flag that distinguishes i915_gem_pin_display from i915_gem_gtt is from node->info_ent->data not the data function parameter. Fixes: 6da84829 ("drm/i915: Focus debugfs/i915_gem_pinned to show...") Signed-off-by:
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Daniel Vetter authored
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