From a57c1bade5a0ee5cd8b74502db9cbebb7f5780b2 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Thu, 29 May 2008 22:10:58 +0100 Subject: libata-sff: Fix oops reported in kerneloops.org for pnp devices with no ctl - Make ata_sff_altstatus private so nobody uses it by mistake - Drop the 400nS delay from it Add ata_sff_irq_status - encapsulates the IRQ check logic This function keeps the existing behaviour for altstatus using devices. I actually suspect the logic was wrong before the changes but -rc isn't the time to play with that ata_sff_sync - ensure writes hit the device Really we want an io* operation for 'is posted' eg ioisposted(ioaddr) so that we can fix the nasty delay this causes on most systems. - ata_sff_pause - 400nS delay Ensure the command hit the device and delay 400nS - ata_sff_dma_pause Ensure the I/O hit the device and enforce an HDMA1:0 transition delay. Requires altstatus register exists, BUG if not so we don't risk corruption in MWDMA modes. (UDMA the checksum will save your backside in theory) The only other complication then is devices with their own handlers. rb532 can use dma_pause but scc needs to access its own altstatus register for internal errata workarounds so directly call the drivers own altstatus function. Signed-off-by: Alan Cox Signed-off-by: Jeff Garzik --- drivers/ata/pata_rb532_cf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/ata/pata_rb532_cf.c') diff --git a/drivers/ata/pata_rb532_cf.c b/drivers/ata/pata_rb532_cf.c index a108d25..f8b3ffc 100644 --- a/drivers/ata/pata_rb532_cf.c +++ b/drivers/ata/pata_rb532_cf.c @@ -57,7 +57,9 @@ static inline void rb532_pata_finish_io(struct ata_port *ap) struct ata_host *ah = ap->host; struct rb532_cf_info *info = ah->private_data; - ata_sff_altstatus(ap); + /* FIXME: Keep previous delay. If this is merely a fence then + ata_sff_sync might be sufficient. */ + ata_sff_dma_pause(ap); ndelay(RB500_CF_IO_DELAY); set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH); -- cgit v1.1