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. >> + .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 -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
