Jeff Garzik wrote:
Mark Lord wrote:
Back in 2.6.17-rc2, a libata module parameter was added for atapi_dmadir.
That's nice, but most SATA devices which need it will tell us about it
in their IDENTIFY PACKET response, as bit-15 of word-62 of the
returned data (as per ATA7, ATA8 specifications).
So for those which specify it, we should automatically use the DMADIR
Otherwise, disc writing will fail by default on many SATA-ATAPI drives.
Signed-off-by: Mark Lord <[EMAIL PROTECTED]>
--- old/drivers/ata/libata-scsi.c 2008-02-18 14:45:08.000000000 -0500
+++ linux/drivers/ata/libata-scsi.c 2008-02-18 14:53:02.000000000
@@ -2543,9 +2543,10 @@
qc->tf.protocol = ATAPI_PROT_DMA;
qc->tf.feature |= ATAPI_PKT_DMA;
- if (atapi_dmadir && (scmd->sc_data_direction != DMA_TO_DEVICE))
- /* some SATA bridges need us to indicate data xfer
- qc->tf.feature |= ATAPI_DMADIR;
+ /* some SATA bridges need us to indicate data xfer direction */
+ if (atapi_dmadir || (dev->id & 0x8000))
+ if (scmd->sc_data_direction != DMA_TO_DEVICE)
+ qc->tf.feature |= ATAPI_DMADIR;
Regardless of the historical usage (or lack thereof) of that I.D. word,
I would prefer
1) an ata version check
2) a simple wrapper in linux/ata.h, similar to the many that already exist
So, conditional ACK...
Good. As I said, I don't expect to be doing this,
so if anyone else wants to fix this issue in libata
they are more than welcome to take the above and build on it.
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