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Date:   Thu, 23 Jun 2022 10:40:40 +0200
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Subject: Re: [PATCH] libata: add horkage for M88V29
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To:     Damien Le Moal <damien.lemoal@opensource.wdc.com>, zboszor@pr.hu,
        linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org
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From:   =?UTF-8?B?QsO2c3rDtnJtw6lueWkgWm9sdMOhbg==?= <zboszor@gmail.com>
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2022. 06. 23. 10:38 keltezéssel, Böszörményi Zoltán írta:
> 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@pr.hu wrote:
>>>>> From: Zoltán Böszörményi <zboszor@gmail.com>
>>>>>
>>>>> 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@gmail.com>
>>>>> ---
>>>>>    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

And also this, which seems to match the sector limit:

[root@chef queue]# cat max_discard_segments
1

>
>>
>>> Best regards,
>>> Zoltán Böszörményi
>>>
>>
>