Re: [radeon r100] when ring test fails, provide users with option to test

From: Christian KÃnig
Date: Mon Nov 30 2015 - 03:40:26 EST


On 29.11.2015 23:22, Pavel Machek wrote:
On Sun 2015-11-29 20:48:53, Christian König wrote:
On 28.11.2015 21:58, Pavel Machek wrote:
Ring test failure is often caused by too high agpmode. Tell the user
what to try.

Signed-off-by: Pavel Machek <pavel@xxxxxx>
NAK, the ring test can fail for any number of reasons and the agpmode is
actually rather unlikely to be the cause.
Well, when I asked on the list "why this is happened" I got "umm,
noone knows" response that was not exactly helpful. And then someone
told me about agpmode.

If you know about the reasons it can fail, could you list them near
the DRM_ERROR, at least as a comment?

Well as I said, that could be any number of reasons. Some of them even completely unrelated to the driver itself.

E.g. BIOS setting, faulty hardware, problems with the writeback etc... There is really not a list you could give here.

Lowering the agpmode usually helps more to prevent random corruptions and problems under load.

Regards,
Christian.


Thanks,
Pavel

Regards,
Christian.

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 238b13f..32b1917 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -3665,7 +3665,7 @@ int r100_ring_test(struct radeon_device *rdev, struct radeon_ring *ring)
if (i < rdev->usec_timeout) {
DRM_INFO("ring test succeeded in %d usecs\n", i);
} else {
- DRM_ERROR("radeon: ring test failed (scratch(0x%04X)=0x%08X)\n",
+ DRM_ERROR("radeon: ring test failed (scratch(0x%04X)=0x%08X), try radeon.agpmode=1?\n",
scratch, tmp);
r = -EINVAL;
}


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