Panic on boot with today's CURRENT, ata related
nate at root.org
Fri Aug 6 16:35:45 PDT 2004
Søren Schmidt wrote:
> Nate Lawson wrote:
>> I took a quick look at this ATA panic. The exact same one occurs for
>> Ceri. A quick dissassemble shows that the testb is the check for the
>> DMA flag at the very end of ata_generic_transaction(). The bug
>> appears to be that this may be a PIO request (since the DMA check is
>> outside the switch() statement). The fix is to make sure it's a DMA
>> request before dereferencing an element of the DMA struct. Try the
>> attached patch.
> No, the fix is to make sure there is a valid ch->dma pointer, the below
> is the correct fix.
> --- ata-lowlevel.c 5 Aug 2004 21:13:41 -0000 1.41
> +++ ata-lowlevel.c 6 Aug 2004 22:31:16 -0000
> @@ -295,7 +295,7 @@
> /* request finish here */
> - if (ch->dma->flags & ATA_DMA_LOADED)
> + if (ch->dma && ch->dma->flags & ATA_DMA_LOADED)
> return ATA_OP_FINISHED;
Thanks. Under what circumstances is a request generated with ATA_R_DMA
set in the flags but where the channel's dma struct has not been allocated?
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