[PATCH v2 1/3] PATA host controller driver for ep93xx

On 2012-04-03 20:55, H Hartley Sweeten wrote:

If the dma init fails does the driver fall back to pio mode correctly?

Yes, udma_mask of ata_port is set only if we successfully requested dma
channels. Otherwise, we are limited to PIO4.

quoted

+	.bmdma_setup		= ep93xx_pata_dma_setup,
+	.bmdma_start		= ep93xx_pata_dma_start,
+	.bmdma_stop		= ep93xx_pata_dma_stop,
+	.bmdma_status		= ep93xx_pata_dma_status,

The bmdma ops pointers are still set if the dma init failed. Should they
be set to NULL?

I think it's not needed. Libata will not call them if udma_mask = 0.

There are only two m2m dma channels on the ep93xx. They could be already in
use by the spi driver. I just want to make sure that the ide driver will fall back to
pio mode if they are not available.

I tested this by enabling ep93xx spi in dma mode. In this case, pata driver
works in PIO4 mode.

Thanks,
RP