Re: [PATCHSET #upstream-fixes] git tree available

[Tejun Heo <htejun@gmail.com>]

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Tejun Heo wrote:
> Mark Lord wrote:
>> Brian & Chamaigne Scamman wrote:
>>> Tejun-
>>>
>>> The hotplug fixes didn't solve the problem. After adding some "logic
>>> monitoring" statements, I found that the successful discovery of the 
>>> drives
>>> depends on the response from sil24_exec_polled_cmd.
>>>
>>> If the call from ata_wait_register is 327680, the drives are 
>>> recognized; if
>>> the response is 262144 the drives have timed out.
>>>
>>> I've also noticed that the drives respond to the EH entering with 
>>> DevExch
>>> vs. PHY RDY changed.
>>>
>>> Bottom line, the drives seem to be recognized almost every time I attach
>>> them to the PMP after the EH has completed processing the empty PMP.  
>>> If the
>>> drives are attached to the PMP before the PMP is attached to the 
>>> controller,
>>> the drives are almost never recognized (EH times out).
> 
> Can you please describe what you did exactly?  sil3726/4726 has some 
> problems when its first fan out port goes online and offline while it's 
> powered up.  You want to keep it occupied at all times.
> 
> Also, does putting sslep(5) right before followup-SRST help?

Can you please test whether the attached patch fixes the detection problem?

-- 
tejun

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diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
index 3374ec5..b65db30 100644
--- a/drivers/ata/libata-pmp.c
+++ b/drivers/ata/libata-pmp.c
@@ -322,9 +322,12 @@ static void sata_pmp_quirks(struct ata_port *ap)
 	if (vendor == 0x1095 && devid == 0x3726) {
 		/* sil3726 quirks */
 		ata_port_for_each_link(link, ap) {
-			/* class code report is unreliable */
+			/* Class code report is unreliable and SRST
+			 * times out under certain configurations.
+			 */
 			if (link->pmp < 5)
-				link->flags |= ATA_LFLAG_ASSUME_ATA;
+				link->flags |= ATA_LFLAG_NO_SRST |
+					       ATA_LFLAG_ASSUME_ATA;
 
 			/* port 5 is for SEMB device and it doesn't like SRST */
 			if (link->pmp == 5)