libata-core: Fix simplex handling
The initial simplex handling code is fooled if you suspend and resume.
This also causes problems with some single channel controllers which
claim to be simplex.
The fix is fairly simple, instead of keeping a flag to remember if we
gave away the simplex channel we remember the actual owner. As the owner
is always part of the host_set we don't even need a refcount.
Knowing the owner also means we can reassign simplex DMA channels in
future hotplug code etc if we need to
Signed-off-by: Alan Cox <alan@redhat.com>
(and a signed-off for the patch I sent before while I remember)
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index ac3d120..eb59f16 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2556,12 +2556,11 @@
* host channels are not permitted to do so.
*/
if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
- ap->host->simplex_claimed = 1;
+ ap->host->simplex_claimed = ap;
/* step5: chip specific finalisation */
if (ap->ops->post_set_mode)
ap->ops->post_set_mode(ap);
-
out:
if (rc)
*r_failed_dev = dev;
@@ -3444,7 +3443,7 @@
"device is on DMA blacklist, disabling DMA\n");
}
- if ((host->flags & ATA_HOST_SIMPLEX) && host->simplex_claimed) {
+ if ((host->flags & ATA_HOST_SIMPLEX) && host->simplex_claimed != ap) {
xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by "
"other device, disabling DMA\n");