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| author | Brian Norris <briannorris@chromium.org> | 2022-03-01 18:11:38 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-14 16:52:35 +0200 |
| commit | 29b62b06774c41d0a5a7bb505bf367120bc70ecd (patch) | |
| tree | f01db485030da46ba027a0264bcaf58b059e4055 | |
| parent | 8189f44270db1be78169e11eec51a3eeb980bc63 (diff) | |
| download | linux-stable-29b62b06774c41d0a5a7bb505bf367120bc70ecd.tar.gz linux-stable-29b62b06774c41d0a5a7bb505bf367120bc70ecd.tar.bz2 linux-stable-29b62b06774c41d0a5a7bb505bf367120bc70ecd.zip | |
drm/bridge: analogix_dp: Grab runtime PM reference for DP-AUX
commit 8fb6c44fe8468f92ac7b8bbfcca4404a4e88645f upstream.
If the display is not enable()d, then we aren't holding a runtime PM
reference here. Thus, it's easy to accidentally cause a hang, if user
space is poking around at /dev/drm_dp_aux0 at the "wrong" time.
Let's get a runtime PM reference, and check that we "see" the panel.
Don't force any panel power-up, etc., because that can be intrusive, and
that's not what other drivers do (see
drivers/gpu/drm/bridge/ti-sn65dsi86.c and
drivers/gpu/drm/bridge/parade-ps8640.c.)
Fixes: 0d97ad03f422 ("drm/bridge: analogix_dp: Remove duplicated code")
Cc: <stable@vger.kernel.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220301181107.v4.1.I773a08785666ebb236917b0c8e6c05e3de471e75@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index 72ec93de0e76..d1077a342f38 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1275,8 +1275,19 @@ static ssize_t analogix_dpaux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) { struct analogix_dp_device *dp = to_dp(aux); + int ret; + + pm_runtime_get_sync(dp->dev); - return analogix_dp_transfer(dp, msg); + ret = analogix_dp_detect_hpd(dp); + if (ret) + goto out; + + ret = analogix_dp_transfer(dp, msg); +out: + pm_runtime_put(dp->dev); + + return ret; } int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev, |