Messages in this thread | | | Date | Tue, 06 Nov 2012 23:55:54 +0100 | From | Sebastian Hesselbarth <> | Subject | Re: [PATCH V2 1/4] arm: mvebu: increase atomic coherent pool size for armada 370/XP |
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On 11/06/2012 11:32 PM, Andrew Lunn wrote: > On Tue, Nov 06, 2012 at 10:28:45PM +0100, S?ren Moch wrote: >> 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'm guess its the DVB sticks which are causing the problems. We have a > number of kirkwood devices with two SATA devices which had problems > until we extended the coherent_pool. The DVB sticks are probably take > more coherent RAM. There was also an issue found recently: > > http://www.spinics.net/lists/arm-kernel/msg203962.html > > That conversation has gone quiet, but that could be because the > participants are at ELCE.
So what is the call here? Should we just increase the coherent buffer size back to what it was before? I am not into this too much but just increasing the buffer will just postpone the actual issue to a later point in running the kernel?
Sebastian
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