Le mardi 14 mai 2013 21:06:16, Tejun Heo a écrit : > Patch looks correct to me but can you please put more detail into the > description preferably with a link to this thread? Updated & attached. I write one (trivial) kernel commit message every 3 years, so please correct me if there is a more consistent way to present it. > As for why atapi_dmadir isn't enabled by default, my memory is extremely > fuzzy now but ISTR it to be deprecated and cause issues with some devices. As atapi_id_dmadir() doesn't detect the bridge needs DMADIR, for now I need to enable it globally. This means it doesn't work out of the box, and needs a reboot to work as atapi_dmadir is read-only in sysfs. Also, if it causes regression with other drives, maybe one would gain a drive by enabling DMADIR but loose another. From my (very limited) understanding, the bridge just passes the drive's "id" (as in "atapi_id_dmadir(dev->id)") through. Is there another way to detect such bridge ? Other things atapi_id_dmadir() should look for in "id" ? If not, would it be possible to have a rw sysfs pseudofile per-device (...per port ?) to enable DMADIR ? If not, what about making atapi_dmadir sysfs pseudofile rw, to save a reboot ? Would you have more ideas on how it could be solved ? I'm willing to give a try to any of these options if they have a chance to get somewhere. Regards, -- Vincent Pelletier
From beca064485e3c86e4abe08b9ce5c89b33ed8c780 Mon Sep 17 00:00:00 2001 Message-Id: <beca064485e3c86e4abe08b9ce5c89b33ed8c780.1368810901.git.plr.vincent@xxxxxxxxx> From: Vincent Pelletier <plr.vincent@xxxxxxxxx> Date: Fri, 17 May 2013 19:09:05 +0200 Subject: libata: make ata_exec_internal_sg honor DMADIR MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixes SATA-to-PATA bridge "Abit Serillel 2" when used on an ATAPI device, which otherwise fails several tries with a timeout until it gets disabled: kernel: ata5.00: qc timeout (cmd 0xa0) kernel: ata5.00: failed to clear UNIT ATTENTION (err_mask=0x5) kernel: ata5.00: disabled Based on a patch by Csaba Halász <csaba.halasz@xxxxxxxxx> on linux-ide: http://marc.info/?l=linux-ide&m=136121147832295&w=2 Signed-off-by: Vincent Pelletier <plr.vincent@xxxxxxxxx> --- drivers/ata/libata-core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 63c743b..d121db7 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -1600,8 +1600,13 @@ unsigned ata_exec_internal_sg(struct ata_device *dev, /* prepare & issue qc */ qc->tf = *tf; - if (cdb) + if (cdb) { memcpy(qc->cdb, cdb, ATAPI_CDB_LEN); + if ((dev->flags & ATA_DFLAG_DMADIR) && + (dma_dir == DMA_FROM_DEVICE)) + /* some SATA bridges need us to indicate data xfer direction */ + qc->tf.feature |= ATAPI_DMADIR; + } qc->flags |= ATA_QCFLAG_RESULT_TF; qc->dma_dir = dma_dir; if (dma_dir != DMA_NONE) { -- 1.7.10.4
