libata: clear SError after link resume

SError used to be cleared in ->postreset.  This has small hotplug race
condition.  If a device is plugged in after reset is complete but
postreset hasn't run yet, its hotplug event gets lost when SError is
cleared.  This patch makes sata_link_resume() clear SError.  This
kills the race condition and makes a lot of sense as some PMP and host
PHYs don't work properly without SError cleared.

This change makes sata_pmp_std_{pre|post}_reset()'s unnecessary as
they become identical to ata_std counterparts.  It also simplifies
sata_pmp_hardreset() and ahci_vt8251_hardreset().

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 0 insertions, 5 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 0f553aaa6f79..a69bcca4eb1b 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1377,7 +1377,6 @@ static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
                                  unsigned long deadline)
 {
         struct ata_port *ap = link->ap;
-        u32 serror;
         bool online;
         int rc;
 
@@ -1388,10 +1387,6 @@ static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
         rc = sata_link_hardreset(link, sata_ehc_deb_timing(&link->eh_context),
                                  deadline, &online, NULL);
 
-        /* vt8251 needs SError cleared for the port to operate */
-        ahci_scr_read(ap, SCR_ERROR, &serror);
-        ahci_scr_write(ap, SCR_ERROR, serror);
-
         ahci_start_engine(ap);
 
         DPRINTK("EXIT, rc=%d, class=%u\n", rc, *class);