sata_via: Correctly setup PIO/DMA for pata slave on vt6421.
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From: Tejun Heo on 19 Jan 2010 22:30 On 01/17/2010 08:56 AM, Bart Hartgers wrote: > Before only the timings for master were set. Datasheet can be found > here: ftp://ftp.vtbridge.org/Docs/Storage/DS_VT6421A_100_CCPL.PDF > Surprisingly, a slave drive works without this patch. According to the > datasheet, the controller by default derives the DMA mode from the > Set Features command issued to a drive. Not sure about the PIO > timings, though. The real problem is that the timings for the master > effectively are the ones tuned for the slave. If these support > different UDMA-settings, there is trouble, especially when the slave > supports a higher UDMA than the master. > > Anyhow, using the same mechanism for both master and slave seems like > a good idea. > > Signed-off-by: Bart Hartgers <bart.hartgers(a)gmail.com> Acked-by: Tejun Heo <tj(a)kernel.org> Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Jeff Garzik on 20 Jan 2010 14:40
On 01/16/2010 06:56 PM, Bart Hartgers wrote: > Before only the timings for master were set. Datasheet can be found > here: ftp://ftp.vtbridge.org/Docs/Storage/DS_VT6421A_100_CCPL.PDF > Surprisingly, a slave drive works without this patch. According to the > datasheet, the controller by default derives the DMA mode from the > Set Features command issued to a drive. Not sure about the PIO > timings, though. The real problem is that the timings for the master > effectively are the ones tuned for the slave. If these support > different UDMA-settings, there is trouble, especially when the slave > supports a higher UDMA than the master. > > Anyhow, using the same mechanism for both master and slave seems like > a good idea. > > Signed-off-by: Bart Hartgers<bart.hartgers(a)gmail.com> applied -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |