Tejun Heo wrote:
With hotplug, PHY always needs to be debounced before a reset as any
reset might find new devices. Extract PHY waiting code from
sata_phy_resume() and extend it to include SStatus debouncing. Note
that sata_phy_debounce() is superset of what used to be done inside
sata_phy_resume().
Three default debounce timing parameters are defined to be used by
hot/boot plug. As resume failure during probing will be properly
handled as errors, timeout doesn't have to be long as before.
probeinit() uses the same timeout to retain the original behavior.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/scsi/libata-core.c | 104 ++++++++++++++++++++++++++++++++++++++------
include/linux/libata.h | 6 +++
2 files changed, 95 insertions(+), 15 deletions(-)
c9aae0f91110060a799f70706bd06ec0dab80cb0
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 009db45..9763395 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -61,6 +61,11 @@ #include <asm/byteorder.h>
#include "libata.h"
+/* debounce timing parameters in msecs { interval, duration, timeout } */
+const unsigned long sata_deb_timing_boot[] = { 5, 100, 2000 };
+const unsigned long sata_deb_timing_eh[] = { 25, 500, 2000 };
+const unsigned long sata_deb_timing_before_fsrst[] = { 100, 2000, 5000 };
+
static unsigned int ata_dev_init_params(struct ata_device *dev,
u16 heads, u16 sectors);
static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
@@ -2427,10 +2432,81 @@ err_out:
DPRINTK("EXIT\n");
}
-static int sata_phy_resume(struct ata_port *ap)
+/**
+ * sata_phy_debounce - debounce SATA phy status
+ * @ap: ATA port to debounce SATA phy status for
+ * @params: timing parameters { interval, duratinon, timeout } in msec
+ *
+ * Make sure SStatus of @ap reaches stable state, determined by
+ * holding the same value where DET is not 1 for @duration polled
+ * every @interval, before @timeout. Timeout constraints the
+ * beginning of the stable state. Because, after hot unplugging,
+ * DET gets stuck at 1 on some controllers, this functions waits
+ * until timeout then returns 0 if DET is stable at 1.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep)
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int sata_phy_debounce(struct ata_port *ap, const unsigned long *params)
{
- unsigned long timeout = jiffies + (HZ * 5);
- u32 scontrol, sstatus;
+ unsigned long interval_msec = params[0];
+ unsigned long duration = params[1] * HZ / 1000;
+ unsigned long timeout = jiffies + params[2] * HZ / 1000;
+ unsigned long last_jiffies;
+ u32 last, cur;
+ int rc;
+
+ if ((rc = sata_scr_read(ap, SCR_STATUS, &cur)))
+ return rc;
+ cur &= 0xf;
+
+ last = cur;
+ last_jiffies = jiffies;
+
+ while (1) {
+ msleep(interval_msec);
+ if ((rc = sata_scr_read(ap, SCR_STATUS, &cur)))
+ return rc;
+ cur &= 0xf;
+
+ /* DET stable? */
+ if (cur == last) {
+ if (cur == 1 && time_before(jiffies, timeout))
+ continue;
+ if (time_after(jiffies, last_jiffies + duration))
+ return 0;
+ continue;
+ }
NAK, changes behavior. We want to preserve the old order of operations
because some PHYs (sata_via and sata_mv come to mind) are a bit
sensitive to being pounded immediately after wakeup.
Jeff
-
: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
