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 --- include/linux/libata.h | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/include/linux/libata.h b/include/linux/libata.h index 93e2b89d0c57..e57e5d08312d 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -1432,7 +1432,8 @@ extern void ata_sff_qc_prep(struct ata_queued_cmd *qc); extern void ata_sff_dumb_qc_prep(struct ata_queued_cmd *qc); extern void ata_sff_dev_select(struct ata_port *ap, unsigned int device); extern u8 ata_sff_check_status(struct ata_port *ap); -extern u8 ata_sff_altstatus(struct ata_port *ap); +extern void ata_sff_pause(struct ata_port *ap); +extern void ata_sff_dma_pause(struct ata_port *ap); extern int ata_sff_busy_sleep(struct ata_port *ap, unsigned long timeout_pat, unsigned long timeout); extern int ata_sff_wait_ready(struct ata_link *link, unsigned long deadline); @@ -1492,19 +1493,6 @@ extern int ata_pci_sff_init_one(struct pci_dev *pdev, struct scsi_host_template *sht, void *host_priv); #endif /* CONFIG_PCI */ -/** - * ata_sff_pause - Flush writes and pause 400 nanoseconds. - * @ap: Port to wait for. - * - * LOCKING: - * Inherited from caller. - */ -static inline void ata_sff_pause(struct ata_port *ap) -{ - ata_sff_altstatus(ap); - ndelay(400); -} - /** * ata_sff_busy_wait - Wait for a port status register * @ap: Port to wait for. -- cgit v1.2.3