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WDCIronportException: Internal
Message-ID: <1665d5a4-994a-b9df-33a9-c748bd5c17be@opensource.wdc.com>
Date:   Thu, 6 Jan 2022 16:55:49 +0900
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.4.0
Subject: Re: [PATCH v4 1/2] ahci: Rename flag `ATA_LFLAG_NO_DB_DELAY` to
 `ATA_LFLAG_NO_DEBOUNCE_DELAY`
Content-Language: en-US
To:     Paul Menzel <pmenzel@molgen.mpg.de>
Cc:     linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20220105153618.2395-1-pmenzel@molgen.mpg.de>
 <d5130eed-d881-f654-3e24-b552609abce9@opensource.wdc.com>
 <e19a8764-2943-f370-f1d9-bb399a2aa1ac@molgen.mpg.de>
From:   Damien Le Moal <damien.lemoal@opensource.wdc.com>
Organization: Western Digital Research
In-Reply-To: <e19a8764-2943-f370-f1d9-bb399a2aa1ac@molgen.mpg.de>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 1/6/22 16:35, Paul Menzel wrote:
> Dear Damien,
> 
> 
> Am 06.01.22 um 03:52 schrieb Damien Le Moal:
>> On 1/6/22 00:36, Paul Menzel wrote:
>>> The new name is longer, but clearer.
>>
>> It looks like you sent an incremental change on top of your previous
>> patches. Please send a cleaned up series. One patch to introduce the
>> ATA_LFLAG_NO_DEBOUNCE_DELAY flag & msleep bypass and another to add the
>> AMD chipset.
>>
>> The commit message of this version patch 2 should be the explanation for
>> the ATA_LFLAG_NO_DEBOUNCE_DELAY flag, not for adding a new chipset ID.
> 
> Sorry, but I think you misread the patch. The flag 
> `ATA_LFLAG_NO_DB_DELAY` exists since commit e39b2bb3b7 (libata: skip 
> debounce delay on link resume).

Arg. Indeed. Ignore my comment :)

Let's wait to see if there are any more comments and I will queue this
up for 5.17.

Going forward, it would be interesting to work on reversing the default:
no delay by default and mark all old & unknown adapters as needing the
delay. As you mentioned, most modern AHCI adapters most likely do not
need it.

Are you willing to take this and send a patches ?

> 
> 
> Kind regards,
> 
> Paul
> 
> 
>>> Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
>>> ---
>>>   drivers/ata/ahci_brcm.c   | 2 +-
>>>   drivers/ata/libata-sata.c | 2 +-
>>>   include/linux/libata.h    | 2 +-
>>>   3 files changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/ata/ahci_brcm.c b/drivers/ata/ahci_brcm.c
>>> index 6e9c5ade4c2ea..649815c196ed0 100644
>>> --- a/drivers/ata/ahci_brcm.c
>>> +++ b/drivers/ata/ahci_brcm.c
>>> @@ -333,7 +333,7 @@ static struct ata_port_operations ahci_brcm_platform_ops = {
>>>   
>>>   static const struct ata_port_info ahci_brcm_port_info = {
>>>   	.flags		= AHCI_FLAG_COMMON | ATA_FLAG_NO_DIPM,
>>> -	.link_flags	= ATA_LFLAG_NO_DB_DELAY,
>>> +	.link_flags	= ATA_LFLAG_NO_DEBOUNCE_DELAY,
>>>   	.pio_mask	= ATA_PIO4,
>>>   	.udma_mask	= ATA_UDMA6,
>>>   	.port_ops	= &ahci_brcm_platform_ops,
>>> diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
>>> index b9c77885b8726..67b2e7cf3cc4e 100644
>>> --- a/drivers/ata/libata-sata.c
>>> +++ b/drivers/ata/libata-sata.c
>>> @@ -317,7 +317,7 @@ int sata_link_resume(struct ata_link *link, const unsigned long *params,
>>>   		 * immediately after resuming.  Delay 200ms before
>>>   		 * debouncing.
>>>   		 */
>>> -		if (!(link->flags & ATA_LFLAG_NO_DB_DELAY))
>>> +		if (!(link->flags & ATA_LFLAG_NO_DEBOUNCE_DELAY))
>>>   			ata_msleep(link->ap, 200);
>>>   
>>>   		/* is SControl restored correctly? */
>>> diff --git a/include/linux/libata.h b/include/linux/libata.h
>>> index 2a8404b26083c..15802e644962d 100644
>>> --- a/include/linux/libata.h
>>> +++ b/include/linux/libata.h
>>> @@ -191,7 +191,7 @@ enum {
>>>   	ATA_LFLAG_NO_LPM	= (1 << 8), /* disable LPM on this link */
>>>   	ATA_LFLAG_RST_ONCE	= (1 << 9), /* limit recovery to one reset */
>>>   	ATA_LFLAG_CHANGED	= (1 << 10), /* LPM state changed on this link */
>>> -	ATA_LFLAG_NO_DB_DELAY	= (1 << 11), /* no debounce delay on link resume */
>>> +	ATA_LFLAG_NO_DEBOUNCE_DELAY = (1 << 11), /* no debounce delay on link resume */
>>>   
>>>   	/* struct ata_port flags */
>>>   	ATA_FLAG_SLAVE_POSS	= (1 << 0), /* host supports slave dev */
>>
>>


-- 
Damien Le Moal
Western Digital Research