Re: [PATCH] libata: add horkage for M88V29

[Damien Le Moal]

On 6/23/22 17:38, Böszörményi Zoltán wrote:
> 2022. 06. 23. 10:22 keltezéssel, Damien Le Moal írta:
>> On 6/23/22 16:47, Böszörményi Zoltán wrote:
>>> 2022. 02. 08. 9:07 keltezéssel, Damien Le Moal írta:
>>>> On 2/4/22 21:57, zboszor@xxxxx wrote:
>>>>> From: Zoltán Böszörményi <zboszor@xxxxxxxxx>
>>>>>
>>>>> This device is a CF card, or possibly an SSD in CF form factor.
>>>>> It supports NCQ and high speed DMA.
>>>>>
>>>>> While it also advertises TRIM support, I/O errors are reported
>>>>> when the discard mount option fstrim is used. TRIM also fails
>>>>> when disabling NCQ and not just as an NCQ command.
>>>>>
>>>>> TRIM must be disabled for this device.
>>>>>
>>>>> Signed-off-by: Zoltán Böszörményi <zboszor@xxxxxxxxx>
>>>>> ---
>>>>>    drivers/ata/libata-core.c | 1 +
>>>>>    1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>>>>> index 67f88027680a..4a7f58fcc411 100644
>>>>> --- a/drivers/ata/libata-core.c
>>>>> +++ b/drivers/ata/libata-core.c
>>>>> @@ -4028,6 +4028,7 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
>>>>>    
>>>>>    	/* devices that don't properly handle TRIM commands */
>>>>>    	{ "SuperSSpeed S238*",		NULL,	ATA_HORKAGE_NOTRIM, },
>>>>> +	{ "M88V29*",			NULL,	ATA_HORKAGE_NOTRIM, },
>>>>>    
>>>>>    	/*
>>>>>    	 * As defined, the DRAT (Deterministic Read After Trim) and RZAT
>>>> Applied to for-5.17-fixes. Thanks !
>>> Thank you. However, I have second thoughts about this patch.
>>> The device advertises this:
>>>
>>> # hdparm -iI /dev/sda
>>> ...
>>>    Enabled Supported
>>>       *    Data Set Management TRIM supported (limit 1 block)
>>> ...
>>>
>>> but the I/O failures always reported higher number of blocks,
>>> IIRC the attempted number of block was 8 or so.
>>>
>>> Can the kernel limit or split TRIM commands according to the
>>> advertised limit? If not (or not yet) then the quirk is good for now.
>> Yes, the kernel does that. See the sysfs queue attributes
>> discard_max_bytes and discard_max_hw_bytes. What are the values for your
>> device ? I think that the "limit 1 block" indicated by hdparm is simply to
>> say that the DSM command (to trim the device) accept only at most a 1
>> block (512 B) list of sectors to trim. That is not the actual trim limit
>> for each sector range in that list.
> 
> With the quirk in effect (TRIM disabled) I have these:
> 
> [root@chef queue]# pwd
> /sys/block/sda/queue
> [root@chef queue]# cat discard_granularity
> 0
> [root@chef queue]# cat discard_max_bytes
> 0
> [root@chef queue]# cat discard_max_hw_bytes
> 0

Yes, expected. What are the values without the quirk applied ?
With 5.19, you can use libata.force to disable/enable it. See
Documentation/admin-guide/kernel-parameters.txt for details.
You could try disabling DSM TRIM (queued trim) and see if the non-ncq trim
work.

-- 
Damien Le Moal
Western Digital Research