Lin,
In the patch d9027470b88631d0956ac37cdadfdeb9cdcf2c99, I did limit the
amount of data cleaning in some of the ata objects.
If setting err_mask to 0 masks the regression I introduced in the
patch, I may have altered too much how ata_device object is
reinitialized when a device is found. I am digging deeper, I may have
change the code to try to preserve the ering as much as possible.
Concerning your patch, isn't adding a test (ent->eflags &
ATA_EFLAG_OLD_ER) in ata_count_probe_trials_cb() more in line with
speed_down_verdict_cb() code?
Gwendal.
On Fri, Apr 20, 2012 at 10:37 AM, Grant Grundler <grundler@xxxxxxxxxx> wrote:
> On Thu, Apr 19, 2012 at 1:16 AM, Lin Ming <ming.m.lin@xxxxxxxxx> wrote:
> ...
>> I did bisect and found that this is a really old regression introduced
>> in 2.6.37-rc1 with below commit.
>>
>> commit d9027470b88631d0956ac37cdadfdeb9cdcf2c99
>> Author: Gwendal Grignou <gwendal@xxxxxxxxxx>
>> Date: Tue May 25 12:31:38 2010 -0700
>>
>> [libata] Add ATA transport class
>>
>> This is a scheleton for libata transport class.
>> All information is read only, exporting information from libata:
>> - ata_port class: one per ATA port
>> - ata_link class: one per ATA port or 15 for SATA Port Multiplier
>> - ata_device class: up to 2 for PATA link, usually one for SATA.
>>
>> Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxx>
>> Reviewed-by: Grant Grundler <grundler@xxxxxxxxxx>
>> Signed-off-by: Jeff Garzik <jgarzik@xxxxxxxxxx>
>>
>>
>> Here is the patch to fix it.
>>
>> Gwendal and Grant,
>>
>> Would you help to review it?
>>
>>
>> From f696daec7ff63e9b3697e8f7ef8f985152667965 Mon Sep 17 00:00:00 2001
>> From: Lin Ming <ming.m.lin@xxxxxxxxx>
>> Date: Thu, 19 Apr 2012 15:45:51 +0800
>> Subject: [PATCH] libata: clear error mask of old error history
>>
>> The old error history was cleared in ata_ering_clear().
>> It only sets ATA_EFLAG_OLD_ER eflags, but the err_mask was not cleared.
>> So ata_ering_map() still iterates the old error history.
>>
>> This causes problem, for example, wrong probe trials count were returned in
>> ata_eh_schedule_probe(), which in turn causes SATA link speed to be slowed down
>> to 1.5Gbps.
>>
>> Reported-by: Martin Mokrejs <mmokrejs@xxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
>
> Reviewed-by: Grant Grundler <grundler@xxxxxxxxxx>
>
> LGTM. Caveat is I have looked at libata code only once or twice since
> reviewing this patch for Gwendal.
>
> cheers,
> grant
>
>> ---
>> drivers/ata/libata-eh.c | 3 ++-
>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
>> index c61316e..4c6f49b 100644
>> --- a/drivers/ata/libata-eh.c
>> +++ b/drivers/ata/libata-eh.c
>> @@ -419,9 +419,10 @@ int ata_ering_map(struct ata_ering *ering,
>> return rc;
>> }
>>
>> -int ata_ering_clear_cb(struct ata_ering_entry *ent, void *void_arg)
>> +static int ata_ering_clear_cb(struct ata_ering_entry *ent, void *void_arg)
>> {
>> ent->eflags |= ATA_EFLAG_OLD_ER;
>> + ent->err_mask = 0;
>> return 0;
>> }
>>
>> --
>> 1.7.2.5
>>
>>
>>
>>>
>>> [ 146.876489] ata6: exception Emask 0x10 SAct 0x0 SErr 0x4050000 action 0xe frozen
>>> [ 146.876499] ata6: irq_stat 0x00400040, connection status changed
>>> [ 146.876508] ata6: SError: { PHYRdyChg CommWake DevExch }
>>> [ 146.876527] ata6: hard resetting link
>>> [ 147.619956] ata6: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
>>> [ 147.869349] ata6.00: ATA-8: ST3000DM001-9YN166, CC4C, max UDMA/133
>>> [ 147.869360] ata6.00: 5860533168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA
>>> [ 147.870126] ata6.00: configured for UDMA/133
>>> [ 147.870131] ata6: EH complete
>>> [ 147.870220] scsi 5:0:0:0: Direct-Access ATA ST3000DM001-9YN1 CC4C PQ: 0 ANSI: 5
>>> [ 147.870391] sd 5:0:0:0: [sdc] 5860533168 512-byte logical blocks: (3.00 TB/2.72 TiB)
>>> [ 147.870393] sd 5:0:0:0: [sdc] 4096-byte physical blocks
>>> [ 147.870396] sd 5:0:0:0: Attached scsi generic sg3 type 0
>>> [ 147.870434] sd 5:0:0:0: [sdc] Write Protect is off
>>> [ 147.870436] sd 5:0:0:0: [sdc] Mode Sense: 00 3a 00 00
>>> [ 147.870460] sd 5:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
>>> [ 147.904848] sdc: sdc1
>>> [ 147.905196] sd 5:0:0:0: [sdc] Attached SCSI disk
>>>
>>>
>>> Here is what happens on re-plug of the device. It is a 3.5" drive and the line
>>> [ 617.838013] ata6: hard resetting link
>>> happens too early. I can hear the drive is still spinning up, it can't be ready yet.
>>> I think the delay should be increased.
>>>
>>>
>>> [ 617.837966] ata6: exception Emask 0x10 SAct 0x0 SErr 0x4050002 action 0xe frozen
>>> [ 617.837976] ata6: irq_stat 0x00400040, connection status changed
>>> [ 617.837984] ata6: SError: { RecovComm PHYRdyChg CommWake DevExch }
>>> [ 617.838004] ata6: limiting SATA link speed to 1.5 Gbps
>>> [ 617.838013] ata6: hard resetting link
>>> [ 623.610941] ata6: link is slow to respond, please be patient (ready=0)
>>> [ 627.864604] ata6: COMRESET failed (errno=-16)
>>> [ 627.864615] ata6: hard resetting link
>>> [ 629.931538] ata6: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
>>> [ 629.932355] ata6.00: ATA-8: ST3000DM001-9YN166, CC4C, max UDMA/133
>>> [ 629.932365] ata6.00: 5860533168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA
>>> [ 629.933170] ata6.00: configured for UDMA/133
>>> [ 629.951629] ata6: EH complete
>>> [ 629.951700] scsi 5:0:0:0: Direct-Access ATA ST3000DM001-9YN1 CC4C PQ: 0 ANSI: 5
>>> [ 629.951816] sd 5:0:0:0: [sdc] 5860533168 512-byte logical blocks: (3.00 TB/2.72 TiB)
>>> [ 629.951819] sd 5:0:0:0: [sdc] 4096-byte physical blocks
>>> [ 629.951842] sd 5:0:0:0: Attached scsi generic sg3 type 0
>>> [ 629.951875] sd 5:0:0:0: [sdc] Write Protect is off
>>> [ 629.951877] sd 5:0:0:0: [sdc] Mode Sense: 00 3a 00 00
>>> [ 629.951901] sd 5:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
>>> [ 629.995970] sdc: sdc1
>>> [ 629.996359] sd 5:0:0:0: [sdc] Attached SCSI disk
>>>
>>>
>>> Martin
>>
>>
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