linux-toradex.git/drivers/gpu/drm/tegra, branch v5.6-rc6

Merge tag 'drm/tegra/for-5.6-rc1-fixes' of git://anongit.freedesktop.org/tegra/linux into drm-next

2020-02-07T02:22:30+00:00

drm/tegra: Fixes for v5.6-rc1

These are a couple of quick fixes for regressions that were found during
the first two weeks of the merge window.

Signed-off-by: Dave Airlie 

From: Thierry Reding 
Link: https://patchwork.freedesktop.org/patch/msgid/20200206172753.2185390-1-thierry.reding@gmail.com

drm/tegra: Reuse IOVA mapping where possible

2020-02-06T17:21:55+00:00

This partially reverts the DMA API support that was recently merged
because it was causing performance regressions on older Tegra devices.
Unfortunately, the cache maintenance performed by dma_map_sg() and
dma_unmap_sg() causes performance to drop by a factor of 10.

The right solution for this would be to cache mappings for buffers per
consumer device, but that's a bit involved. Instead, we simply revert to
the old behaviour of sharing IOVA mappings when we know that devices can
do so (i.e. they share the same IOMMU domain).

Cc:  # v5.5
Reported-by: Dmitry Osipenko 
Signed-off-by: Thierry Reding 
Tested-by: Dmitry Osipenko 
Reviewed-by: Dmitry Osipenko

drm/tegra: Relax IOMMU usage criteria on old Tegra

2020-02-06T17:21:14+00:00

Older Tegra devices only allow addressing 32 bits of memory, so whether
or not the host1x is attached to an IOMMU doesn't matter. host1x IOMMU
attachment is only needed on devices that can address memory beyond the
32-bit boundary and where the host1x doesn't support the wide GATHER
opcode that allows it to access buffers at higher addresses.

Cc:  # v5.5
Signed-off-by: Thierry Reding 
Tested-by: Dmitry Osipenko 
Reviewed-by: Dmitry Osipenko

drm/tegra: sor: Initialize runtime PM before use

2020-01-31T20:29:24+00:00

Commit fd67e9c6ed5a ("drm/tegra: Do not implement runtime PM") replaced
the generic runtime PM usage by a host1x bus-specific implementation in
order to work around some assumptions baked into runtime PM that are in
conflict with the requirements in the Tegra DRM driver.

Unfortunately the new runtime PM callbacks are not setup yet at the time
when the SOR driver first needs to resume the device to register the SOR
pad clock, and accesses to register will cause the system to hang.

Note that this only happens on Tegra124 and Tegra210 because those are
the only SoCs where the SOR pad clock is registered from the SOR driver.
Later generations use a SOR pad clock provided by the BPMP.

Fix this by moving the registration of the SOR pad clock after the
host1x client has been registered. That's somewhat suboptimal because
this could potentially, though it's very unlikely, cause the Tegra DRM
to be probed if the SOR happens to be the last subdevice to register,
only to be immediately removed again if the SOR pad output clock fails
to register. That's just a minor annoyance, though, and doesn't justify
implementing a workaround.

Fixes: fd67e9c6ed5a ("drm/tegra: Do not implement runtime PM")
Signed-off-by: Thierry Reding

drm/tegra: sor: Disable runtime PM on probe failure

2020-01-31T20:29:16+00:00

If the driver fails to probe, make sure to disable runtime PM again.

While at it, make the cleanup code in ->remove() symmetric.

Signed-off-by: Thierry Reding

drm/tegra: sor: Suspend on clock registration failure

2020-01-31T20:29:05+00:00

Make sure the SOR module is suspenden after we fail to register the SOR
pad output clock.

Signed-off-by: Thierry Reding

Merge tag 'drm/tegra/for-5.6-rc1' of git://anongit.freedesktop.org/tegra/linux into drm-next

2020-01-15T06:21:28+00:00

drm/tegra: Changes for v5.6-rc1

This contains a small set of mostly fixes and some minor improvements.

Signed-off-by: Dave Airlie 

From: Thierry Reding 
Link: https://patchwork.freedesktop.org/patch/msgid/20200111004835.2412858-1-thierry.reding@gmail.com

drm/tegra: output: Implement system suspend/resume

2020-01-10T15:46:29+00:00

Implement generic system suspend/resume functions that can be used with
any output type. Currently this only implements disabling and enabling
of the IRQ functionality across system suspend/resume. This prevents an
interrupt from happening before the display driver has fully resumed.

Signed-off-by: Thierry Reding

drm/tegra: sor: Mark PM functions as __maybe_unused

2020-01-10T15:39:07+00:00

Without CONFIG_PM, some functions cause harmless warnings:

drivers/gpu/drm/tegra/sor.c:3984:12: error: 'tegra_sor_resume' defined but not used [-Werror=unused-function]
 static int tegra_sor_resume(struct device *dev)
            ^~~~~~~~~~~~~~~~
drivers/gpu/drm/tegra/sor.c:3970:12: error: 'tegra_sor_suspend' defined but not used [-Werror=unused-function]
 static int tegra_sor_suspend(struct device *dev)
            ^~~~~~~~~~~~~~~~~

Mark these as __maybe_unused so the compiler can drop them
silently.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Thierry Reding

drm/tegra: Do not implement runtime PM

2020-01-10T15:37:43+00:00

The Tegra DRM driver heavily relies on the implementations for runtime
suspend/resume to be called at specific times. Unfortunately, there are
some cases where that doesn't work. One example is if the user disables
runtime PM for a given subdevice. Another example is that the PM core
acquires a reference to runtime PM during system sleep, effectively
preventing devices from going into low power modes. This is intentional
to avoid nasty race conditions, but it also causes system sleep to not
function properly on all Tegra systems.

Fix this by not implementing runtime PM at all. Instead, a minimal,
reference-counted suspend/resume infrastructure is added to the host1x
bus. This has the benefit that it can be used regardless of the system
power state (or any transitions we might be in), or whether or not the
user allows runtime PM.

Atomic modesetting guarantees that these functions will end up being
called at the right point in time, so the pitfalls for the more generic
runtime PM do not apply here.

Signed-off-by: Thierry Reding