linux-kernel - [PATCH 1/3] aspeed-video: add error message for unhandled interrupts

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Message-Id: <20201215024542.18888-2-zev@bewilderbeest.net>
Date:   Mon, 14 Dec 2020 20:45:40 -0600
From:   Zev Weiss <zev@...ilderbeest.net>
To:     Eddie James <eajames@...ux.ibm.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Joel Stanley <joel@....id.au>,
        Andrew Jeffery <andrew@...id.au>, linux-media@...r.kernel.org,
        openbmc@...ts.ozlabs.org, linux-arm-kernel@...ts.infradead.org,
        linux-aspeed@...ts.ozlabs.org, linux-kernel@...r.kernel.org
Cc:     Zev Weiss <zev@...ilderbeest.net>,
        Jae Hyun Yoo <jae.hyun.yoo@...ux.intel.com>
Subject: [PATCH 1/3] aspeed-video: add error message for unhandled interrupts

This device seems to have a propensity for asserting interrupts that
aren't enabled -- in addition to the CAPTURE_COMPLETE and FRAME_COMPLETE
interrupts squashed in commit 65d270acb2d662c3346793663ac3a759eb4491b8,
COMP_READY has also been observed.  Adding a message diagnosing what
happened in the event of unhandled interrupt status bits should
hopefully make the debugging process simpler for any others that pop up
in the future.

Signed-off-by: Zev Weiss <zev@...ilderbeest.net>
---
 drivers/media/platform/aspeed-video.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index 7d98db1d9b52..eb02043532e3 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c
@@ -562,6 +562,7 @@ static irqreturn_t aspeed_video_irq(int irq, void *arg)
 {
 	struct aspeed_video *video = arg;
 	u32 sts = aspeed_video_read(video, VE_INTERRUPT_STATUS);
+	u32 orig_sts = sts;
 
 	/*
 	 * Resolution changed or signal was lost; reset the engine and
@@ -639,6 +640,10 @@ static irqreturn_t aspeed_video_irq(int irq, void *arg)
 	if (sts & VE_INTERRUPT_FRAME_COMPLETE)
 		sts &= ~VE_INTERRUPT_FRAME_COMPLETE;
 
+	if (sts)
+		dev_err_ratelimited(video->dev, "unexpected interrupt asserted:"
+				    " sts=%08x, orig_sts=%08x", sts, orig_sts);
+
 	return sts ? IRQ_NONE : IRQ_HANDLED;
 }
 
-- 
2.29.2