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drm/bridge: ti-sn65dsi83: Fix error handling in sn65dsi83_reset_work()

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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>
This commit is contained in:
Esben Haabendal 2026-08-31 14:21:32 +02:00 committed by Luca Ceresoli
parent ed761e0693
commit 4600b4d1a9
1 changed files with 4 additions and 2 deletions
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6
drivers/gpu/drm/bridge/ti-sn65dsi83.c
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@ -403,7 +403,7 @@ static int sn65dsi83_reset_pipe(struct sn65dsi83 *sn65dsi83)
drm_modeset_drop_locks(&ctx);
drm_modeset_acquire_fini(&ctx);
return 0;
return err;
}
static void sn65dsi83_reset_work(struct work_struct *ws)
@ -419,11 +419,13 @@ static void sn65dsi83_reset_work(struct work_struct *ws)
ret = sn65dsi83_reset_pipe(ctx);
if (ret) {
dev_err(ctx->dev, "reset pipe failed %pe\n", ERR_PTR(ret));
return;
goto bridge_exit;
}
if (ctx->irq)
enable_irq(ctx->irq);
bridge_exit:
drm_bridge_exit(idx);
}