libata: Keep shadow last_ctl up to date during resets
libata keeps a shadow copy of the ATA CTL register (which is write only),
and only writes to the hardware when the required value doesn't match
the shadow. However this copy wasn't being maintained when performing
reset functions. This could cause problems for the first operation after
a reset when the correct value might not be written to the CTL register.
This problem was observed when hotplugging a drive: the identify command
was being issued with interrupts enabled, when they should have been
disabled.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 714cb04..f93dc02 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -2066,6 +2066,7 @@
iowrite8(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
udelay(20); /* FIXME: flush */
iowrite8(ap->ctl, ioaddr->ctl_addr);
+ ap->last_ctl = ap->ctl;
/* wait the port to become ready */
return ata_sff_wait_after_reset(&ap->link, devmask, deadline);
@@ -2190,8 +2191,10 @@
}
/* set up device control */
- if (ap->ioaddr.ctl_addr)
+ if (ap->ioaddr.ctl_addr) {
iowrite8(ap->ctl, ap->ioaddr.ctl_addr);
+ ap->last_ctl = ap->ctl;
+ }
}
EXPORT_SYMBOL_GPL(ata_sff_postreset);
@@ -2534,6 +2537,7 @@
if (ap->flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST)) {
/* set up device control for ATA_FLAG_SATA_RESET */
iowrite8(ap->ctl, ioaddr->ctl_addr);
+ ap->last_ctl = ap->ctl;
}
DPRINTK("EXIT\n");