| Message ID | 1438448070-32552-1-git-send-email-mark.cave-ayland@ilande.co.uk |
|---|---|
| State | New |
| Headers | show |
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 <mark.cave-ayland@ilande.co.uk> > --- 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. Aurelien
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 <mark.cave-ayland@ilande.co.uk> >> --- > > 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.
On 08/01/2015 02:54 PM, Mark Cave-Ayland wrote: > 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 <mark.cave-ayland@ilande.co.uk> >>> --- >> >> 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. > Definitely a 2.4.1/2.5 thing anyway at this time. If you prepare a v3 to nail down the last state transition error message you're seeing, just CC stable as well, and I'll handle it for 2.5. --js
diff --git a/hw/ide/macio.c b/hw/ide/macio.c index a55a479..bd245e9 100644 --- a/hw/ide/macio.c +++ b/hw/ide/macio.c @@ -247,8 +247,12 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret) /* Non-block ATAPI transfer - just copy to RAM */ s->io_buffer_size = MIN(s->io_buffer_size, io->len); cpu_physical_memory_write(io->addr, s->io_buffer, s->io_buffer_size); - ide_atapi_cmd_ok(s); - m->dma_active = false; + + /* Invoke callback as we would at the end of a standard block + transfer */ + s->io_buffer_size = 0; + io->len = 0; + pmac_ide_atapi_transfer_cb(io, 0); goto done; }
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 <mark.cave-ayland@ilande.co.uk> --- v2: add missing goto hw/ide/macio.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)