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From: Colin Ian King <colin.king@canonical.com>
To: "Anthony Koo" <Anthony.Koo@amd.com>,
	"Harry Wentland" <harry.wentland@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"David (ChunMing) Zhou" <David1.Zhou@amd.com>,
	"David Airlie" <airlied@linux.ie>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Nicholas Kazlauskas" <nicholas.kazlauskas@amd.com>,
	amd-gfx@lists.freedesktop.org,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: re: drm/amd/display: make PSR static screen entry within 30 ms
Date: Fri, 17 Jan 2020 13:17:33 +0000	[thread overview]
Message-ID: <d4fb24b4-bc95-4684-bb09-3cf4df8b3c2c@canonical.com> (raw)

Hi,

Static analysis with Coverity has detected a division by zero in the
following commit:

commit 5b5abe9526073ccbf3032d27b5864520829cdd9c
Author: Anthony Koo <Anthony.Koo@amd.com>
Date:   Mon Dec 9 17:26:34 2019 -0500

    drm/amd/display: make PSR static screen entry within 30 ms

Specifically:

       unsigned int vsync_rate_hz = 0;
       struct dc_static_screen_params params = {0};
       /* Calculate number of static frames before generating interrupt to
        * enter PSR.
        */
       unsigned int frame_time_microsec = 1000000 / vsync_rate_hz;

vsync_rate_hz is zero, and frame_time_microsec is being assigned a value
that is being divided by zero.  I'm not sure why this is coded this way
and not sure what the fix is, hence I'm reporting the issue.

Colin

                 reply	other threads:[~2020-01-17 13:17 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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