kernel/linux.git/drivers/gpu/drm/tegra/dc.c, branch v5.15.215

drm/tegra: dc: Fix device node reference leak in tegra_dc_has_output()

2026-07-24T13:51:30+00:00

[ Upstream commit 63a3998d792ab5c45304bf879e385a31fa923b61 ] The of_for_each_phandle() macro increments the reference count of the device node it iterates over. If the loop exits early, the reference must be released manually. In tegra_dc_has_output(), the function returns true immediately when a match is found, failing to release the current node's reference. Fix this by adding a call to of_node_put() before returning from the loop. Fixes: c57997bce423 ("drm/tegra: sor: Add Tegra186 support") Signed-off-by: Felix Gu Acked-by: Mikko Perttunen Signed-off-by: Thierry Reding Link: https://patch.msgid.link/20260128-dc-v1-1-a88205826301@gmail.com Signed-off-by: Sasha Levin

drm/tegra: dc: Fix reference leak in tegra_dc_couple()

2025-12-06T21:09:31+00:00

commit 4c5376b4b143c4834ebd392aef2215847752b16a upstream. driver_find_device() calls get_device() to increment the reference count once a matching device is found, but there is no put_device() to balance the reference count. To avoid reference count leakage, add put_device() to decrease the reference count. Found by code review. Cc: stable@vger.kernel.org Fixes: a31500fe7055 ("drm/tegra: dc: Restore coupling of display controllers") Signed-off-by: Ma Ke Acked-by: Mikko Perttunen Signed-off-by: Thierry Reding Link: https://patch.msgid.link/20251022114720.24937-1-make24@iscas.ac.cn Signed-off-by: Greg Kroah-Hartman

drm/tegra: Fix a possible null pointer dereference

2025-07-10T13:57:40+00:00

commit 780351a5f61416ed2ba1199cc57e4a076fca644d upstream. In tegra_crtc_reset(), new memory is allocated with kzalloc(), but no check is performed. Before calling __drm_atomic_helper_crtc_reset, state should be checked to prevent possible null pointer dereference. Fixes: b7e0b04ae450 ("drm/tegra: Convert to using __drm_atomic_helper_crtc_reset() for reset.") Cc: stable@vger.kernel.org Signed-off-by: Qiu-ji Chen Signed-off-by: Thierry Reding Link: https://lore.kernel.org/r/20241106095906.15247-1-chenqiuji666@gmail.com Signed-off-by: Greg Kroah-Hartman

drm/tegra: Assign plane type before registration

2025-07-10T13:57:40+00:00

commit 9ff4fdf4f44b69237c0afc1d3a8dac916ce66f3e upstream. Changes to a plane's type after it has been registered aren't propagated to userspace automatically. This could possibly be achieved by updating the property, but since we can already determine which type this should be before the registration, passing in the right type from the start is a much better solution. Suggested-by: Aaron Kling Signed-off-by: Thierry Reding Cc: stable@vger.kernel.org Fixes: 473079549f27 ("drm/tegra: dc: Add Tegra186 support") Signed-off-by: Aaron Kling Signed-off-by: Thierry Reding Link: https://lore.kernel.org/r/20250421-tegra-drm-primary-v2-1-7f740c4c2121@gmail.com Signed-off-by: Greg Kroah-Hartman

drm/tegra: dc: rgb: Allow changing PLLD rate on Tegra30+

2024-03-26T22:21:24+00:00

[ Upstream commit 0c921b6d4ba06bc899fd84d3ce1c1afd3d00bc1c ] Asus Transformer TF700T is a Tegra30 tablet device which uses RGB->DSI bridge that requires a precise clock rate in order to operate properly. Tegra30 has a dedicated PLL for each display controller, hence the PLL rate can be changed freely. Allow PLL rate changes on Tegra30+ for RGB output. Configure the clock rate before display controller is enabled since DC itself may be running off this PLL and it's not okay to change the rate of the active PLL that doesn't support dynamic frequency switching since hardware will hang. Tested-by: Maxim Schwalm #TF700T Signed-off-by: Dmitry Osipenko Signed-off-by: Thierry Reding Stable-dep-of: bc456b5d93db ("drm/tegra: rgb: Fix some error handling paths in tegra_dc_rgb_probe()") Signed-off-by: Sasha Levin

drm/tegra: Add missing clk_disable_unprepare() in tegra_dc_probe()

2022-12-31T12:14:13+00:00

[ Upstream commit 7ad4384d53c67672a8720cdc2ef638d7d1710ab8 ] Add the missing clk_disable_unprepare() before return from tegra_dc_probe() in the error handling path. Fixes: f68ba6912bd2 ("drm/tegra: dc: Link DC1 to DC0 on Tegra20") Signed-off-by: Zhang Zekun Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

drm/tegra: dc: Remove unused variables

2021-09-16T16:06:50+00:00

Remove unused variables from tegra_crtc_update_memory_bandwidth(). Fixes: 04d5d5df9df7 ("drm/tegra: dc: Support memory bandwidth management") Reported-by: kernel test robot Signed-off-by: Dmitry Osipenko Reviewed-by: Mikko Perttunen Signed-off-by: Thierry Reding

drm/tegra: dc: Extend debug stats with total number of events

2021-08-13T10:31:07+00:00

It's useful to know the total number of underflow events and currently the debug stats are getting reset each time CRTC is being disabled. Let's account the overall number of events that doesn't get a reset. Reviewed-by: Michał Mirosław Signed-off-by: Dmitry Osipenko Signed-off-by: Thierry Reding

drm/tegra: dc: Support memory bandwidth management

2021-08-13T10:30:33+00:00

Display controller (DC) performs isochronous memory transfers, and thus, has a requirement for a minimum memory bandwidth that shall be fulfilled, otherwise framebuffer data can't be fetched fast enough and this results in a DC's data-FIFO underflow that follows by a visual corruption. The Memory Controller drivers provide facility for memory bandwidth management via interconnect API. Let's wire up the interconnect API support to the DC driver in order to fix the distorted display output on T30 Ouya, T124 TK1 and other Tegra devices. Tested-by: Peter Geis # Ouya T30 Tested-by: Matt Merhar # Ouya T30 Tested-by: Nicolas Chauvet # PAZ00 T20 and TK1 T124 Signed-off-by: Dmitry Osipenko [treding@nvidia.com: unbreak Tegra186+ display support] Signed-off-by: Thierry Reding

Merge tag 'drm/tegra/for-5.14-rc1' of ssh://git.freedesktop.org/git/tegra/linux into drm-next

2021-06-23T04:24:37+00:00

drm/tegra: Changes for v5.14-rc1 The two major changes here are fixed YUV support as well as scaling on Tegra186 and later. This allows Tegra DRM to be used, for example, as a video sink for the kmssink gstreamer plugin. The remainder of the changes are minor fixes. Signed-off-by: Dave Airlie From: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20210611165157.3569315-1-thierry.reding@gmail.com