[PATCH 1/2 v3] libata-pmp: add schedule timeout to support some PMP cards

[<r66093@freescale.com>]

From: Jerry Huang <Chang-Ming.Huang@freescale.com>

With Freescale SATA controller, some PMP cards(e.g JMB393 PMP card)
can't work on some platforms (e.g mpc837x, p1022):
During PMP initialize, when reading the PMP SCR, we will observe the TIMEOUT
error because PMP card SCR is not ready.
Therefore, we need enough time to wait for the PMP card ready for SCR read.

below is the error log:
fsl-sata e0018000.sata: Sata FSL Platform/CSB Driver init
scsi0 : sata_fsl
ata1: SATA max UDMA/133 irq 44
ata1: Signature Update detected @ 504 msecs
ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2.15: Port Multiplier 1.2, 0x197b:0x0325 r0, 15 ports, feat 0x5/0xf
ata2.00: hard resetting link
ata2.15: qc timeout (cmd 0xe4)
ata2.00: failed to read SCR 0 (Emask=0x4)
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2: ATA_SRST issue failed
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2.00: reset failed, giving up
ata2.15: hard resetting link
ata2: Hardreset failed, not off-lined 0
ata2: No Signature Update
ata2.15: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2.00: hard resetting link
ata2.15: qc timeout (cmd 0xe4)
ata2.00: failed to read SCR 0 (Emask=0x4)
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2: ATA_SRST issue failed
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2.00: reset failed, giving up
ata2.15: hard resetting link
ata2: Hardreset failed, not off-lined 0
ata2: No Signature Update
ata2.15: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2.00: hard resetting link
ata2.15: qc timeout (cmd 0xe4)
ata2.00: failed to read SCR 0 (Emask=0x4)
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2: ATA_SRST issue failed
ata2.00: failed to read SCR 0 (Emask=0x40)
ata2.00: reset failed, giving up
ata2.00: failed to recover link after 3 tries, disabling
ata2.15: hard resetting link
ata2: Hardreset failed, not off-lined 0
ata2: No Signature Update
ata2.15: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2.15: qc timeout (cmd 0xe4)
ata2.00: failed to read SCR 0 (Emask=0x4)
ata2.00: failed to write SCR 1 (Emask=0x40)
ata2.00: failed to clear SError.N (errno=-5)
ata2.15: hard resetting link
ata2: Hardreset failed, not off-lined 0
ata2: No Signature Update
ata2.15: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2.01: hard resetting link
ata2.01: failed to resume link (SControl 0)
ata2.01: SATA link down (SStatus 0 SControl 0)
ata2.02: hard resetting link
ata2.02: failed to resume link (SControl 0)
ata2.02: SATA link down (SStatus 0 SControl 0)
......
ata2.14: hard resetting link
ata2.14: failed to resume link (SControl 0)
ata2.14: SATA link down (SStatus 0 SControl 0)
ata2: EH complete

Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
CC: Jeff Garzik <jgarzik@pobox.com>
---
changes for v2:
	- use function msecs_to_jiffies to calculate the jiffies for 1ms
	- cleanup the code
changes for v3:
	- add the quirks to support pmp card
	- add the CC

 drivers/ata/libata-pmp.c |   12 ++++++++++++
 include/linux/libata.h   |    1 +
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
index 21b80c5..d7d4bb5 100644
--- a/drivers/ata/libata-pmp.c
+++ b/drivers/ata/libata-pmp.c
@@ -146,6 +146,13 @@ int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *r_val)
 	if (reg > SATA_PMP_PSCR_CONTROL)
 		return -EINVAL;
 
+	/* For some PMP card, we need delay some time */
+	if (link->flags & ATA_LFLAG_DELAY) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		/* sleep 50 msecond */
+		schedule_timeout(msecs_to_jiffies(50));
+	}
+
 	err_mask = sata_pmp_read(link, reg, r_val);
 	if (err_mask) {
 		ata_link_warn(link, "failed to read SCR %d (Emask=0x%x)\n",
@@ -456,6 +463,11 @@ static void sata_pmp_quirks(struct ata_port *ap)
 				       ATA_LFLAG_NO_SRST |
 				       ATA_LFLAG_ASSUME_ATA;
 		}
+	} else if (vendor == 0x197b && devid == 0x0325) {
+		/* For jmicron JMB393 card, need some time to ready the PMP */
+		ata_for_each_link(link, ap, EDGE) {
+			link->flags |= ATA_LFLAG_DELAY;
+		}
 	}
 }
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index cafc09a..c23ddf9 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -182,6 +182,7 @@ enum {
 	ATA_LFLAG_DISABLED	= (1 << 6), /* link is disabled */
 	ATA_LFLAG_SW_ACTIVITY	= (1 << 7), /* keep activity stats */
 	ATA_LFLAG_NO_LPM	= (1 << 8), /* disable LPM on this link */
+	ATA_LFLAG_DELAY		= (1 << 9), /* delay some time */
 
 	/* struct ata_port flags */
 	ATA_FLAG_SLAVE_POSS	= (1 << 0), /* host supports slave dev */
-- 
1.7.5.4