On 1/12/24 03:10, Sergei Shtylyov wrote:
> On 1/11/24 2:51 PM, Damien Le Moal wrote:
>
>> This reverts commit fd3a6837d8e18cb7be80dcca1283276290336a7a.
>>
>> Several users have signaled issues with commit fd3a6837d8e1 ("ata:
>> libata-core: Fix ata_pci_shutdown_one()") which causes failure of the
>> system SoC to go to a low power state. The reason for this problem
>> is not well understood but given that this patch is harmless with the
>> improvements to ata_dev_power_set_standby(), restore it to allow system
>> lower power state transitions.
>>
>> For regular system shutdown, ata_dev_power_set_standby() will be
>> executed twice: once the scsi device is removed and another when
>> ata_pci_shutdown_one() executes and EH completes unloading the devices.
>> Make the second call to ata_dev_power_set_standby() do nothing by using
>> ata_dev_power_is_active() and return if the device is already in
>> standby.
>>
>> Fixes: fd3a6837d8e1 ("ata: libata-core: Fix ata_pci_shutdown_one()")
>> Cc: stable@xxxxxxxxxxxxxxx
>> Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
>> ---
>> drivers/ata/libata-core.c | 75 +++++++++++++++++++++++----------------
>> 1 file changed, 45 insertions(+), 30 deletions(-)
>>
>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>> index d9f80f4f70f5..20a366942626 100644
>> --- a/drivers/ata/libata-core.c
>> +++ b/drivers/ata/libata-core.c
>> @@ -2001,6 +2001,33 @@ bool ata_dev_power_init_tf(struct ata_device *dev, struct ata_taskfile *tf,
>> return true;
>> }
>>
>> +static bool ata_dev_power_is_active(struct ata_device *dev)
>> +{
>> + struct ata_taskfile tf;
>> + unsigned int err_mask;
>> +
>> + ata_tf_init(dev, &tf);
>> + tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
>
> Why set ATA_TFLAG_ISADDR, BTW? This command doesn't use any taskfile
> regs but the device/head reg. Material for a fix, I guess... :-)
Good point. I will look into it. This code was moved from libata-scsi
translation, so it has been like this for a very long time...
>
>> + tf.protocol = ATA_PROT_NODATA;
>> + tf.command = ATA_CMD_CHK_POWER;
>> +
> [...]
>
> MBR, Sergey
--
Damien Le Moal
Western Digital Research
