[PATCH] drm/rockchip: vop: Add timeout for DSP hold

[PATCH] drm/rockchip: vop: Add timeout for DSP hold

[Brian Norris]

If hardware is malfunctioning (e.g., misconfigured clocks?), we can get
stuck here forever, holding various DRM locks and eventually locking up
the entire system. It's better to complain loudly and move on, than to
lock up the system.

In local tests, this operation takes less than 20ms.

Signed-off-by: Brian Norris <briannorris@chromium.org>
---

 drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index ba9e14da41b4..b28ea5d6a3e2 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -726,7 +726,9 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc,
 
 	spin_unlock(&vop->reg_lock);
 
-	wait_for_completion(&vop->dsp_hold_completion);
+	if (!wait_for_completion_timeout(&vop->dsp_hold_completion,
+					 msecs_to_jiffies(200)))
+		WARN(1, "%s: timed out waiting for DSP hold", crtc->name);
 
 	vop_dsp_hold_valid_irq_disable(vop);
 
-- 
2.33.0.882.g93a45727a2-goog

Re: [PATCH] drm/rockchip: vop: Add timeout for DSP hold

[Heiko Stuebner]

On Fri, 8 Oct 2021 15:31:04 -0700, Brian Norris wrote:
> If hardware is malfunctioning (e.g., misconfigured clocks?), we can get
> stuck here forever, holding various DRM locks and eventually locking up
> the entire system. It's better to complain loudly and move on, than to
> lock up the system.
> 
> In local tests, this operation takes less than 20ms.

Applied, thanks!

[1/1] drm/rockchip: vop: Add timeout for DSP hold
      commit: 085af7d28897deb08a4f64a29e55525f963cc041

Best regards,
-- 
Heiko Stuebner <heiko@sntech.de>