It's theoretically possible for the runtime PM reference to leak if the
code fails anywhere between the pm_runtime_resume_and_get() and
pm_runtime_put() calls, so make sure to release the runtime PM reference
in that case.
Practically this will never happen because none of the functions will
fail on Tegra, but it's better for the code to be pedantic in case these
assumptions will ever become wrong.
Change-Id: I04d11da45f88ccbae5b007e73344232914480f77
Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
[treding@nvidia.com: add commit message]
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2545947
Reviewed-by: svc_kernel_abi <svc_kernel_abi@nvidia.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit
The SOR resets are exclusively shared with the SOR power domain. This
means that exclusive access can only be granted temporarily and in order
for that to work, a rigorous sequence must be observed. To ensure that a
single consumer gets exclusive access to a reset, each consumer must
implement a rigorous protocol using the reset_control_acquire() and
reset_control_release() functions.
However, these functions alone don't provide any guarantees at the
system level. Drivers need to ensure that the only a single consumer has
access to the reset at the same time. In order for the SOR to be able to
exclusively access its reset, it must therefore ensure that the SOR
power domain is not powered off by holding on to a runtime PM reference
to that power domain across the reset assert/deassert operation.
This used to work fine by accident, but was revealed when recently more
devices started to rely on the SOR power domain.
Change-Id: Ifdb94bcafc452e1f2cccd532e98670bf05425ccd
Fixes: 11c632e1cfd3 ("drm/tegra: sor: Implement acquire/release for reset")
Reported-by: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2545939
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: svc_kernel_abi <svc_kernel_abi@nvidia.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit
Add the upstream tegra-drm driver with the 'Host1x/Tegra UAPI' series
[0] applied. This driver will be built as an external module for testing
and development with upstream Linux kernels.
The following modifications have been made to the series posted upstream
1. Update the Makefile to always build the driver as a module
2. Always enable the tegra_drm_ioctl_xxx in the tegra_drm_ioctls and
remove the dependency on CONFIG_DRM_TEGRA_STAGING.
3. Rename the include/uapi/drm/tegra_drm.h to
include/uapi/drm/tegra_drm_next.h to avoid conflicts with upstream
headers when building as an external module.
5. Rename the module that is built to be tegra-drm-next.ko instead of
tegra-drm.ko to avoid any depmod conflicts with the upstream driver.
[0] https://patchwork.ozlabs.org/project/linux-tegra/list/?series=215770
Bug 3156385
Change-Id: I19206f989325c9c6ff3c2b9301d964140d52234f
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2435802
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit
