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  1. 19 Mar, 2023 37 commits
  3. 18 Mar, 2023 3 commits
    • Sakari Ailus's avatar
      media: v4l: subdev: Make link validation safer · 55f1ecb1
      Sakari Ailus authored 
      Link validation currently accesses invalid pointers if the link passed to
it is not between two sub-devices. This is of course a driver bug.

Ignore the error but print a warning message, as this is how it used to
work previously.

Fixes: a6b995ed ("media: subdev: use streams in v4l2_subdev_link_validate()")
Reported-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
      55f1ecb1
    • Tomi Valkeinen's avatar
      media: subdev: Fix validation state lockdep issue · 53077915
      Tomi Valkeinen authored 
      The new subdev state code has a possible deadlock scenario during link
validation when the pipeline contains subdevs that support state and
that do not support state.

The current code locks the states of the subdevs on both ends of the
link when starting the link validation, locking the sink side first,
then the source. If either (or both) of the subdevs does not support
state, nothing is done for that subdev at this point, and instead the
locking is handled the old way, i.e. the subdev's ops do the locking
internally.

The issue arises when the sink doesn't support state, but source does,
so the validation code locks the source for the duration of the
validation, and then the sink is locked only when the get_fmt op is
called. So lockdep sees the source locked first, then the sink.

Later, when the streaming is started, the sink's s_stream op is called,
which probably takes the subdev's lock. The op then calls the source's
s_stream, which takes the source's lock. So, the sink is locked first,
then the source.

Note that link validation and stream starting is not done at the same
time, so an actual deadlock should never happen. However, it's still a
clear bug.

Fix this by locking the subdev states only if both subdevs support
state. In other words, we have two scenarios:

1. Both subdevs support state. Lock sink first, then source, and keep
   the locks while validating the link.
2. At least one of the subdevs do not support state. Take the lock only
   for the duration of the operation (get_fmt or looking at the
   routing), and release after the op is done.

Obviously 1. is better, as we have a more consistent view of the states
of the subdevs during validation. 2. is how it has been so far, so it's
no worse than this used to be.
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
      53077915
    • Arnd Bergmann's avatar
      media: i2c: imx290: fix conditional function definitions · b928db94
      Arnd Bergmann authored 
      The runtime suspend/resume functions are only referenced from the
dev_pm_ops, but they use the old SET_RUNTIME_PM_OPS() helper
that requires a __maybe_unused annotation to avoid a warning:

drivers/media/i2c/imx290.c:1082:12: error: unused function 'imx290_runtime_resume' [-Werror,-Wunused-function]
static int imx290_runtime_resume(struct device *dev)
           ^
drivers/media/i2c/imx290.c:1090:12: error: unused function 'imx290_runtime_suspend' [-Werror,-Wunused-function]
static int imx290_runtime_suspend(struct device *dev)
           ^

Convert this to the new RUNTIME_PM_OPS() helper that so this
is not required. To improve this further, also use the pm_ptr()
helper that lets the dev_pm_ops get dropped entirely when
CONFIG_PM is disabled.

A related mistake happened in the of_match_ptr() macro here, which
like SET_RUNTIME_PM_OPS() requires the match table to be marked
as __maybe_unused, though I could not reproduce building this without
CONFIG_OF. Remove the of_match_ptr() here as there is no point in
dropping the match table in configurations without CONFIG_OF.

Fixes: 02852c01 ("media: i2c: imx290: Initialize runtime PM before subdev")
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
      b928db94
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