sata_nv: Use notifier for completion checks
The hardware provides us a notifier register that indicates what command
tags have completed. Use this to determine which CPBs to check, rather
than blindly checking all active CPBs. This should provide a minor
performance win, since if the controller has touched some of these
incomplete CPBs, accessing them will likely result in a cache miss.
Signed-off-by: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index 57dace4..745d856 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -854,22 +854,14 @@
if (status & (NV_ADMA_STAT_DONE |
NV_ADMA_STAT_CPBERR)) {
+ u32 check_commands = notifier | notifier_error;
+ int pos, error = 0;
/** Check CPBs for completed commands */
-
- if (ata_tag_valid(ap->active_tag)) {
- /* Non-NCQ command */
- nv_adma_check_cpb(ap, ap->active_tag,
- notifier_error & (1 << ap->active_tag));
- } else {
- int pos, error = 0;
- u32 active = ap->sactive;
-
- while ((pos = ffs(active)) && !error) {
- pos--;
- error = nv_adma_check_cpb(ap, pos,
- notifier_error & (1 << pos) );
- active &= ~(1 << pos );
- }
+ while ((pos = ffs(check_commands)) && !error) {
+ pos--;
+ error = nv_adma_check_cpb(ap, pos,
+ notifier_error & (1 << pos) );
+ check_commands &= ~(1 << pos );
}
}
}