From c55af1f5abf606118b32e3ce9c3b1bbce5236e7e Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 11 Feb 2009 13:08:42 -0800 Subject: [PATCH] [libata] pata_legacy: for VLB 32bit PIO don't try tricks with slop These devices are generally used with ATA anyway and it seems that some ATAPI will need us to issue the right number of words. Therefore as we can't switch mid burst on VLB devices we should only use 32bit I/O for suitable block sizes. Signed-off-by: Andrew Morton Signed-off-by: Jeff Garzik --- drivers/ata/pata_legacy.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/ata/pata_legacy.c b/drivers/ata/pata_legacy.c index 6c1d778b63a9..e3bc1b436284 100644 --- a/drivers/ata/pata_legacy.c +++ b/drivers/ata/pata_legacy.c @@ -283,9 +283,10 @@ static void pdc20230_set_piomode(struct ata_port *ap, struct ata_device *adev) static unsigned int pdc_data_xfer_vlb(struct ata_device *dev, unsigned char *buf, unsigned int buflen, int rw) { - if (ata_id_has_dword_io(dev->id)) { + int slop = buflen & 3; + /* 32bit I/O capable *and* we need to write a whole number of dwords */ + if (ata_id_has_dword_io(dev->id) && (slop == 0 || slop == 3)) { struct ata_port *ap = dev->link->ap; - int slop = buflen & 3; unsigned long flags; local_irq_save(flags); @@ -735,7 +736,7 @@ static unsigned int vlb32_data_xfer(struct ata_device *adev, unsigned char *buf, struct ata_port *ap = adev->link->ap; int slop = buflen & 3; - if (ata_id_has_dword_io(adev->id)) { + if (ata_id_has_dword_io(adev->id) && (slop == 0 || slop == 3)) { if (rw == WRITE) iowrite32_rep(ap->ioaddr.data_addr, buf, buflen >> 2); else -- 2.39.5