Re: [PATCH 1/1] AHCI: disabled FBS prior to issuing software reset

From: Sergei Shtylyov
Date: Sat Sep 28 2013 - 11:23:40 EST


On 28-09-2013 15:13, Xiangliang Yu wrote:

If device is attached to port multiplier, the detection process
look like this:
ahci_hardreset(link, class, deadline)
if (class == ATA_DEV_PMP) {
sata_pmp_attach(dev) /* will enable FBS */
sata_pmp_init_links(ap, nr_ports);
ata_for_each_link(link, ap, EDGE) {
sata_std_hardreset(link, class, deadline);
if (link_is_online)
ahci_softreset(link, class, deadline);
But, according to chapter 9.3.9 in AHCI spec: Prior to issuing software reset,
software shall clear PxCMD.ST to '0' and then clear PxFBS.EN to '0'.

Signed-off-by: Xiangliang Yu <yxlraid@xxxxxxxxx>
drivers/ata/libahci.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index acfd0f7..8d024a4 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1267,9 +1267,11 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class,
struct ata_port *ap = link->ap;
struct ahci_host_priv *hpriv = ap->host->private_data;
+ struct ahci_port_priv *pp = ap->private_data;
const char *reason = NULL;
unsigned long now, msecs;
struct ata_taskfile tf;
+ bool flag = FALSE;

Why not lowercase 'false'? And this is not a good name for a variable (too generic), it should better be called 'fbs' or something...

@@ -1279,6 +1281,11 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class,
if (rc && rc != -EOPNOTSUPP)
ata_link_warn(link, "failed to reset engine (errno=%d)\n", rc);

+ if (!ata_is_host_link(link) && pp->fbs_enabled) {
+ ahci_disable_fbs(ap);
+ flag = TRUE;

Why not lowercase 'true'?

WBR, Sergei

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