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Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers t
From: |
Mark Cave-Ayland |
Subject: |
Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers |
Date: |
Sat, 01 Aug 2015 19:54:47 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 |
On 01/08/15 19:33, Aurelien Jarno wrote:
> On 2015-08-01 17:54, Mark Cave-Ayland wrote:
>> The existing code incorrectly changes the dma_active flag when a non-block
>> transfer has completed leading to a hang on newer versions of Linux because
>> the
>> IDE and DMA engines deadlock waiting for each other.
>>
>> Instead copy the buffer directly to RAM, set the remaining transfer size to
>> 0 and
>> then invoke the ATAPI callback manually once again to correctly finish the
>> transfer in an identical manner to a block transfer.
>>
>> Signed-off-by: Mark Cave-Ayland <address@hidden>
>> ---
>
> Thanks for the patch, it improves things here. I don't get messages
> anymore, and I get less messages when mounting the CD-ROM, though I
> still get one:
>
> [ 307.258463] pata-macio 0.00021000:ata-4: timeout flushing DMA
> [ 307.262856] ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
> [ 307.262919] ata2.00: BMDMA stat 0x6
> [ 307.263048] sr 1:0:0:0: CDB: Get configuration: 46 00 00 28 00 00 00 00
> 10 00
> [ 307.263289] ata2.00: cmd a0/01:00:00:10:00/00:00:00:00:00/a0 tag 0 dma
> 16400 in
> [ 307.263297] res 41/50:03:00:10:00/00:00:00:00:00/a0 Emask 0x20
> (host bus error)
> [ 307.263407] ata2.00: status: { DRDY ERR }
> [ 307.271251] ata2.00: configured for MWDMA2
> [ 307.271824] ata2: EH complete
>
> The CD-ROM is fully functional though.
Hmmmm yes I can recreate that here - must be another transition between
the non-block and the block transfer code (I was working on eliminating
the boot messages) caused by reading the disc metadata upon mount.
Unfortunately I don't have much time to work on this right now so maybe
it's a 2.4.1/2.5 thing unless John can take a look?
ATB,
Mark.
- [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers, Mark Cave-Ayland, 2015/08/01
- Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers, Aurelien Jarno, 2015/08/01
- Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers,
Mark Cave-Ayland <=
- Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers, Mark Cave-Ayland, 2015/08/13
- Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers, John Snow, 2015/08/13
- Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers, Aurelien Jarno, 2015/08/18
- Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers, John Snow, 2015/08/21
- Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers, Mark Cave-Ayland, 2015/08/21
- Re: [Qemu-devel] [PATCHv2] macio: handle non-block ATAPI DMA transfers the same as block DMA transfers, John Snow, 2015/08/24