The error handling of sn65dsi83_reset_pipe() in sn65dsi83_reset_work() has
seen a couple of changes that seems to cause a bit of confusion.
While sn65dsi83_reset_work() has implemented an early exit if
sn65dsi83_reset_pipe() fails since it was added, when a commit from Maxime
Ripard switched to use drm_bridge_helper_reset_crtc() [1] the
sn65dsi83_reset_pipe() function would no longer return an error code, so
the early exit was then a no-op, and even on sn65dsi83_reset_pipe()
failure, enable_irq() has been called.
When drm_bridge_enter()/drm_bridge_exit() resource protection was added,
the drm_bridge_exit() incidentally was always called, which is the correct
approach. But only because the early exit in sn65dsi83_reset_pipe() was
never hit because sn65dsi83_reset_pipe() always returns 0.
In order get back to a situation where enable_irq() is not called on
sn65dsi83_reset_pipe() failure, which should help protect against irq
storms, we need to reintroduce a non-zero return value from
sn65dsi83_reset_pipe() on error, and fix sn65dsi83_reset_work() so that we
always exit the DRM bridge critical section with drm_bridge_exit().
[1] commit e17fadff7a ("drm/bridge: ti-sn65dsi83: Switch to drm_bridge_helper_reset_crtc")
[2] commit d2e8d1bc84 ("drm/bridge: ti-sn65dsi83: protect device resources on unplug")
Fixes: e17fadff7a ("drm/bridge: ti-sn65dsi83: Switch to drm_bridge_helper_reset_crtc")
Cc: stable@vger.kernel.org
Signed-off-by: Esben Haabendal <esben@geanix.com>
Reviewed-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patch.msgid.link/20260831-ti-sn65dsi83-fixes-v5-1-e712765d6c4f@geanix.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
4600b4d1a9