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5 commits

Author SHA1 Message Date
Dmitry Baryshkov
51474ab44a drm/bridge: aux-hpd-bridge: correct devm_drm_dp_hpd_bridge_add() stub
If CONFIG_DRM_AUX_HPD_BRIDGE is not enabled, the aux-bridge.h header
provides a stub for the bridge's functions. Correct the arguments list
of one of those stubs to match the argument list of the non-stubbed
function.

Fixes: e5ca263508 ("drm/bridge: aux-hpd: separate allocation and registration")
Reported-by: kernel test robot <lkp@intel.com>
Cc: stable <stable@kernel.org>
Closes: https://lore.kernel.org/oe-kbuild-all/202405110428.TMCfb1Ut-lkp@intel.com/
Cc: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240511-fix-aux-hpd-stubs-v1-1-98dae71dfaec@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-11 13:02:14 +01:00
Johan Hovold
e5ca263508 drm/bridge: aux-hpd: separate allocation and registration
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
2024-02-23 17:00:56 +02:00
Nathan Chancellor
812cc1da7f drm/bridge: Return NULL instead of plain 0 in drm_dp_hpd_bridge_register() stub
sparse complains:

  drivers/usb/typec/tcpm/qcom/qcom_pmic_typec.c: note: in included file:
  include/drm/bridge/aux-bridge.h:29:16: sparse: sparse: Using plain integer as NULL pointer

Return NULL to clear up the warning.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312060025.BdeqZrWx-lkp@intel.com/
Fixes: e560518a6c ("drm/bridge: implement generic DP HPD bridge")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231205-drm_aux_bridge-fixes-v1-3-d242a0ae9df4@kernel.org
2023-12-07 12:28:03 +02:00
Dmitry Baryshkov
e560518a6c drm/bridge: implement generic DP HPD bridge
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
2023-12-04 16:07:29 +02:00
Dmitry Baryshkov
2a04739139 drm/bridge: add transparent bridge helper
Define a helper for creating simple transparent bridges which serve the
only purpose of linking devices into the bridge chain up to the last
bridge representing the connector. This is especially useful for
DP/USB-C bridge chains, which can span across several devices, but do
not require any additional functionality from the intermediate bridges.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231203114333.1305826-2-dmitry.baryshkov@linaro.org
2023-12-04 16:07:29 +02:00