* [PATCH] drm/sun4i: dsi: Avoid hotplug race with DRM driver bind
@ 2020-02-17 6:09 Samuel Holland
2020-02-19 15:57 ` Maxime Ripard
0 siblings, 1 reply; 2+ messages in thread
From: Samuel Holland @ 2020-02-17 6:09 UTC (permalink / raw)
To: Maxime Ripard, Chen-Yu Tsai, David Airlie, Daniel Vetter, dri-devel
Cc: linux-arm-kernel, linux-kernel, stable, Samuel Holland
We need to make sure that the DRM driver is fully registered before
allowing the panel to be attached. Otherwise, we may trigger a hotplug
event before sun4i_framebuffer_init() sets up drm->mode_config.funcs,
causing a NULL pointer dereference.
Fixes: 1a2703bd7356 ("drm/sun4i: dsi: Allow binding the host without a panel")
Signed-off-by: Samuel Holland <samuel@sholland.org>
---
This fixes a bug in my previous patch series, that I didn't catch until
it was already merged.
---
drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 9aa78c73873c..9cc1bb69fcda 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -970,7 +970,7 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,
if (IS_ERR(panel))
return PTR_ERR(panel);
- if (!dsi->drm)
+ if (!dsi->drm || !dsi->drm->registered)
return -EPROBE_DEFER;
dsi->panel = panel;
--
2.24.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] drm/sun4i: dsi: Avoid hotplug race with DRM driver bind
2020-02-17 6:09 [PATCH] drm/sun4i: dsi: Avoid hotplug race with DRM driver bind Samuel Holland
@ 2020-02-19 15:57 ` Maxime Ripard
0 siblings, 0 replies; 2+ messages in thread
From: Maxime Ripard @ 2020-02-19 15:57 UTC (permalink / raw)
To: Samuel Holland
Cc: Chen-Yu Tsai, David Airlie, Daniel Vetter, dri-devel,
linux-arm-kernel, linux-kernel, stable
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On Mon, Feb 17, 2020 at 12:09:06AM -0600, Samuel Holland wrote:
> We need to make sure that the DRM driver is fully registered before
> allowing the panel to be attached. Otherwise, we may trigger a hotplug
> event before sun4i_framebuffer_init() sets up drm->mode_config.funcs,
> causing a NULL pointer dereference.
>
> Fixes: 1a2703bd7356 ("drm/sun4i: dsi: Allow binding the host without a panel")
> Signed-off-by: Samuel Holland <samuel@sholland.org>
Thanks for following up on this, I've applied it
Maxime
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^ permalink raw reply [flat|nested] 2+ messages in thread
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