| Message ID | 20221013110411.1674359-2-treapking@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Clean up it6505 driver and improve synchronization | expand |
On Thu, 13 Oct 2022 at 13:04, Pin-yen Lin <treapking@chromium.org> wrote: > > During device boot, the HPD interrupt could be triggered before the DRM > subsystem registers it6505 as a DRM bridge. In such cases, the driver > tries to access AUX channel and causes NULL pointer dereference. > Initializing the AUX channel earlier to prevent such error. > > Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver") > Signed-off-by: Pin-yen Lin <treapking@chromium.org> > --- > > (no changes since v1) > > drivers/gpu/drm/bridge/ite-it6505.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c > index a4302492cf8d..f7f6c3e20fae 100644 > --- a/drivers/gpu/drm/bridge/ite-it6505.c > +++ b/drivers/gpu/drm/bridge/ite-it6505.c > @@ -2871,10 +2871,7 @@ static int it6505_bridge_attach(struct drm_bridge *bridge, > } > > /* Register aux channel */ > - it6505->aux.name = "DP-AUX"; > - it6505->aux.dev = dev; > it6505->aux.drm_dev = bridge->dev; > - it6505->aux.transfer = it6505_aux_transfer; > > ret = drm_dp_aux_register(&it6505->aux); > > @@ -3354,6 +3351,11 @@ static int it6505_i2c_probe(struct i2c_client *client, > debugfs_init(it6505); > pm_runtime_enable(dev); > > + it6505->aux.name = "DP-AUX"; > + it6505->aux.dev = dev; > + it6505->aux.transfer = it6505_aux_transfer; > + drm_dp_aux_init(&it6505->aux); > + > it6505->bridge.funcs = &it6505_bridge_funcs; > it6505->bridge.type = DRM_MODE_CONNECTOR_DisplayPort; > it6505->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | > -- > 2.38.0.rc1.362.ged0d419d3c-goog > Reviewed-by: Robert Foss <robert.foss@linaro.org>
diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c index a4302492cf8d..f7f6c3e20fae 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -2871,10 +2871,7 @@ static int it6505_bridge_attach(struct drm_bridge *bridge, } /* Register aux channel */ - it6505->aux.name = "DP-AUX"; - it6505->aux.dev = dev; it6505->aux.drm_dev = bridge->dev; - it6505->aux.transfer = it6505_aux_transfer; ret = drm_dp_aux_register(&it6505->aux); @@ -3354,6 +3351,11 @@ static int it6505_i2c_probe(struct i2c_client *client, debugfs_init(it6505); pm_runtime_enable(dev); + it6505->aux.name = "DP-AUX"; + it6505->aux.dev = dev; + it6505->aux.transfer = it6505_aux_transfer; + drm_dp_aux_init(&it6505->aux); + it6505->bridge.funcs = &it6505_bridge_funcs; it6505->bridge.type = DRM_MODE_CONNECTOR_DisplayPort; it6505->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID |
During device boot, the HPD interrupt could be triggered before the DRM subsystem registers it6505 as a DRM bridge. In such cases, the driver tries to access AUX channel and causes NULL pointer dereference. Initializing the AUX channel earlier to prevent such error. Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver") Signed-off-by: Pin-yen Lin <treapking@chromium.org> --- (no changes since v1) drivers/gpu/drm/bridge/ite-it6505.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)