Re: [PATCH V2 1/4] arm: mvebu: increase atomic coherent pool sizefor armada 370/XP

From: Sören Moch
Date: Tue Nov 06 2012 - 16:29:21 EST


resent as plain text, sorry.


> For Armada 370/XP we have the same problem that for the commit
> cb01b63, so we applied the same solution: "The default 256 KiB
> coherent pool may be too small for some of the Kirkwood devices, so
> increase it to make sure that devices will be able to allocate their
> buffers with GFP_ATOMIC flag"

I see a regression from linux-3.5 to linux-3.6 and think there might be a fundamental problem
with this patch. On my Kirkwood system (guruplug server plus) with linux-3.6.2 I see following
errors and corresponding malfunction even with further increased (2M, 4M) pool size:

Oct 19 00:41:22 guru kernel: ERROR: 4096 KiB atomic DMA coherent pool is too small!
Oct 19 00:41:22 guru kernel: Please increase it with coherent_pool= kernel parameter!

So I had to downgrade to linux-3.5 which is running without problems.

I use SATA and several DVB sticks (em28xx / drxk and dib0700).

I already sent this bug report to m.szyprowski and gregory.clementearlier, but
Sebastian suggested to send it to the mailing list and the responsible maintainers, too.

Please write to my e-mail directly if you have further questions or patches for me to test.

Regards,
Soeren

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/