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Daniel Drake authored
On 38+ Intel-based ASUS products, the NVIDIA GPU becomes unusable after S3 suspend/resume. The affected products include multiple generations of NVIDIA GPUs and Intel SoCs. After resume, nouveau logs many errors such as: fifo: fault 00 [READ] at 0000005555555000 engine 00 [GR] client 04 [HUB/FE] reason 4a [] on channel -1 [007fa91000 unknown] DRM: failed to idle channel 0 [DRM] Similarly, the NVIDIA proprietary driver also fails after resume (black screen, 100% CPU usage in Xorg process). We shipped a sample to NVIDIA for diagnosis, and their response indicated that it's a problem with the parent PCI bridge (on the Intel SoC), not the GPU. Runtime suspend/resume works fine, only S3 suspend is affected. We found a workaround: on resume, rewrite the Intel PCI bridge 'Prefetchable Base Upper 32 Bits' register (PCI_PREF_BASE_UPPER32). In the cases that I checked, this register has value 0 and we just have to rewrite that value. Linux already saves and restores PCI config space during suspend/resume, but this register was being skipped because upon resume, it already has value 0 (the correct, pre-suspend value). Intel appear to have previously acknowledged this behaviour and the requirement to rewrite this register: https://bugzilla.kernel.org/show_bug.cgi?id=116851#c23 Based on that, rewrite the prefetch register values even when that appears unnecessary. We have confirmed this solution on all the affected models we have in-hands (X542UQ, UX533FD, X530UN, V272UN). Additionally, this solves an issue where r8169 MSI-X interrupts were broken after S3 suspend/resume on ASUS X441UAR. This issue was recently worked around in commit 7bb05b85 ("r8169: don't use MSI-X on RTL8106e"). It also fixes the same issue on RTL6186evl/8111evl on an Aimfor-tech laptop that we had not yet patched. I suspect it will also fix the issue that was worked around in commit 7c53a722 ("r8169: don't use MSI-X on RTL8168g"). Thomas Martitz reports that this change also solves an issue where the AMD Radeon Polaris 10 GPU on the HP Zbook 14u G5 is unresponsive after S3 suspend/resume. Link: https://bugzilla.kernel.org/show_bug.cgi?id=201069Signed-off-by:
Daniel Drake <drake@endlessm.com> Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> Reviewed-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-By:
Peter Wu <peter@lekensteyn.nl> CC: stable@vger.kernel.org
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