[PATCH v2] ata: libata-pmp: add JMicron JMS562 quirk

[raoxu]

From: Xu Rao <raoxu@xxxxxxxxxxxxx>

JMicron JMS562, as used in QNAP QDA-A2AR RAID1 adapters, may
keep the exported ATA device not ready while the array is rebuilding.

In this state, libata may repeatedly try to softreset and classify
the fan-out link.  On the affected adapter, this can time out, make
PMP/SCR access fail, and eventually disable the fan-out link before
the RAID volume is exported.

A failing boot shows the fan-out link failing SRST, PMP access
timing out, SCR read failing, and the link being disabled:

  ata4.00: softreset failed (device not ready)
  ata4.15: qc timeout after 3000 msecs (cmd 0xe4)
  ata4.00: failed to read SCR 0 (Emask=0x4)
  ata4.00: failed to recover link after 3 tries, disabling

After that, the root filesystem on the exported RAID volume cannot
be found.

Add JMS562 to the existing JMicron PMP quirk that disables LPM,
avoids softreset on fan-out links, and assumes an ATA device.  This
prevents libata from dropping the exported RAID volume during rebuild
recovery.

Signed-off-by: Xu Rao <raoxu@xxxxxxxxxxxxx>
---
v2:
- Fix the subject prefix.  The previous submission was incorrectly
  sent as [PATCH 6/6], but this is a standalone patch.
- No code changes.

 drivers/ata/libata-pmp.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
index e3adc008fed1..f4103438ac7d 100644
--- a/drivers/ata/libata-pmp.c
+++ b/drivers/ata/libata-pmp.c
@@ -446,8 +446,13 @@ static void sata_pmp_quirks(struct ata_port *ap)
 		 * otherwise.  Don't try hard to recover it.
 		 */
 		ap->pmp_link[ap->nr_pmp_links - 1].flags |= ATA_LFLAG_NO_RETRY;
-	} else if (vendor == 0x197b && (devid == 0x2352 || devid == 0x0325)) {
+	} else if (vendor == 0x197b &&
+		   (devid == 0x0562 || devid == 0x2352 || devid == 0x0325)) {
 		/*
+		 * 0x0562: JMicron JMS562, as used in QNAP QDA-A2AR RAID1
+		 *         adapters.  The exported device may stay not ready
+		 *         while the array is rebuilding, and SRST/classify can
+		 *         time out before the RAID volume is exported.
 		 * 0x2352: found in Thermaltake BlackX Duet, jmicron JMB350?
 		 * 0x0325: jmicron JMB394.
 		 */
--
2.50.1