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path: root/drivers/gpu/drm/bridge/aux-hpd-bridge.c
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2025-07-10drm/bridge: aux-hpd-bridge: fix assignment of the of_nodeDmitry Baryshkov1-1/+2
[ Upstream commit e8537cad824065b0425fb0429e762e14a08067c2 ] Perform fix similar to the one in the commit 85e444a68126 ("drm/bridge: Fix assignment of the of_node of the parent to aux bridge"). The assignment of the of_node to the aux HPD bridge needs to mark the of_node as reused, otherwise driver core will attempt to bind resources like pinctrl, which is going to fail as corresponding pins are already marked as used by the parent device. Fix that by using the device_set_of_node_from_dev() helper instead of assigning it directly. Fixes: e560518a6c2e ("drm/bridge: implement generic DP HPD bridge") Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://lore.kernel.org/r/20250608-fix-aud-hpd-bridge-v1-1-4641a6f8e381@oss.qualcomm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23drm/bridge: aux-hpd: separate allocation and registrationJohan Hovold1-15/+52
Combining allocation and registration is an anti-pattern that should be avoided. Add two new functions for allocating and registering an dp-hpd bridge with a proper 'devm' prefix so that it is clear that these are device managed interfaces. devm_drm_dp_hpd_bridge_alloc() devm_drm_dp_hpd_bridge_add() The new interface will be used to fix a use-after-free bug in the Qualcomm PMIC GLINK driver and may prevent similar issues from being introduced elsewhere. The existing drm_dp_hpd_bridge_register() is reimplemented using the above and left in place for now. Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Reviewed-by: Bjorn Andersson <andersson@kernel.org> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20240217150228.5788-3-johan+linaro@kernel.org
2024-02-23drm/bridge: aux-hpd: fix OF node leaksJohan Hovold1-0/+3
The two device node references taken during allocation need to be dropped when the auxiliary device is freed. Fixes: 6914968a0b52 ("drm/bridge: properly refcount DT nodes in aux bridge drivers") Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Neil Armstrong <neil.armstrong@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Reviewed-by: Bjorn Andersson <andersson@kernel.org> Link: https://lore.kernel.org/r/20240217150228.5788-2-johan+linaro@kernel.org Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20240217150228.5788-2-johan+linaro@kernel.org
2023-12-19drm/bridge: properly refcount DT nodes in aux bridge driversDmitry Baryshkov1-2/+2
The aux-bridge and aux-hpd-bridge drivers didn't call of_node_get() on the device nodes further used for dev->of_node and platform data. When bridge devices are released, the reference counts are decreased, resulting in refcount underflow / use-after-free warnings. Get corresponding refcounts during AUX bridge allocation. Reported-by: Luca Weiss <luca.weiss@fairphone.com> Fixes: 2a04739139b2 ("drm/bridge: add transparent bridge helper") Fixes: 26f4bac3d884 ("drm/bridge: aux-hpd: Replace of_device.h with explicit include") Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20231216235910.911958-1-dmitry.baryshkov@linaro.org Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
2023-12-07drm/bridge: aux-hpd: Replace of_device.h with explicit includeRob Herring1-1/+1
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it was merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. Soon the implicit includes are going to be removed. of_device.h isn't needed, but of.h is for of_node_put(). Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://lore.kernel.org/r/20231207162501.2629952-1-robh@kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
2023-12-04drm/bridge: implement generic DP HPD bridgeDmitry Baryshkov1-0/+163
Several USB-C controllers implement a pretty simple DRM bridge which implements just the HPD notification operations. Add special helper for creating such simple bridges. Acked-by: Neil Armstrong <neil.armstrong@linaro.org> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20231203114333.1305826-5-dmitry.baryshkov@linaro.org