From: Olaf Hering The hald media changed polling does really confuse things. Noone knows why the delays are needed, but they give us access to the CD. An udelay(50) will give reliable access to the drive, but there is still one (or more) EH reset. The drive works without EH resets with udelay(100). Signed-off-by: Olaf Hering Signed-off-by: Andrew Morton --- drivers/ata/pata_sl82c105.c | 3 +++ 1 file changed, 3 insertions(+) diff -puN drivers/ata/pata_sl82c105.c~add-delay-around-sl82c105_reset_engine-calls drivers/ata/pata_sl82c105.c --- a/drivers/ata/pata_sl82c105.c~add-delay-around-sl82c105_reset_engine-calls +++ a/drivers/ata/pata_sl82c105.c @@ -187,7 +187,9 @@ static void sl82c105_bmdma_start(struct { struct ata_port *ap = qc->ap; + udelay(100); sl82c105_reset_engine(ap); + udelay(100); /* Set the clocks for DMA */ sl82c105_configure_dmamode(ap, qc->dev); @@ -216,6 +218,7 @@ static void sl82c105_bmdma_stop(struct a ata_bmdma_stop(qc); sl82c105_reset_engine(ap); + udelay(100); /* This will redo the initial setup of the DMA device to matching PIO timings */ _