Re: [PATCH 1/2] ata: ahci: Refactor ahci_broken_lpm()

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 9-Jun-25 4:49 PM, Hans de Goede wrote:
> Hi Niklas,
> 
> On 9-Jun-25 3:45 PM, Niklas Cassel wrote:
>> Currently, the match table in ahci_broken_lpm() contains DMI BIOS dates
>> of BIOSes that are known to be working.
>>
>> Having a list of known to be working versions is usually the wrong way to
>> do things (as this list could theoretically be infinite).
>>
>> Refactor this match table to contain DMI BIOS dates of BIOSes that are
>> known to not be working, such that this list can be extended with BIOS
>> versions (for other boards) that are known to not be working, where there
>> is no good BIOS version (because all released versions are broken).
>>
>> Signed-off-by: Niklas Cassel <cassel@kernel.org>
>> ---
>>  drivers/ata/ahci.c | 34 ++++++++++++++++++++++++----------
>>  1 file changed, 24 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
>> index 163ac909bd06..a6ce172fa928 100644
>> --- a/drivers/ata/ahci.c
>> +++ b/drivers/ata/ahci.c
>> @@ -1411,27 +1411,39 @@ static bool ahci_broken_suspend(struct pci_dev *pdev)
>>  static bool ahci_broken_lpm(struct pci_dev *pdev)
>>  {
>>  	static const struct dmi_system_id sysids[] = {
>> -		/* Various Lenovo 50 series have LPM issues with older BIOSen */
>> +		/* Table contains DMI BIOS dates of BIOSes with broken LPM. */
>>  		{
>>  			.matches = {
>>  				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
>>  				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X250"),
>>  			},
>> -			.driver_data = "20180406", /* 1.31 */
>> +			/*
>> +			 * 1.31, released 20180406, has working LPM, mark any
>> +			 * DMI BIOS date before that as broken.
>> +			 */
> 
> Note the DMI_BIOS_DATE field is the data the BIOS was build, I would avoid
> the word "released" here since release-notes doucments often contain different
> dates then the actual build date (e.g. see below).
> 
>> +			.driver_data = "20180405",
>>  		},
>>  		{
>>  			.matches = {
>>  				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
>>  				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad L450"),
>>  			},
>> -			.driver_data = "20180420", /* 1.28 */
>> +			/*
>> +			 * 1.28, released 20180420, has working LPM, mark any
>> +			 * DMI BIOS date before that as broken.
>> +			 */
>> +			.driver_data = "20180419",
>>  		},
>>  		{
>>  			.matches = {
>>  				DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
>>  				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T450s"),
>>  			},
>> -			.driver_data = "20180315", /* 1.33 */
>> +			/*
>> +			 * 1.33, released 20180315, has working LPM, mark any
>> +			 * DMI BIOS date before that as broken.
>> +			 */
>> +			.driver_data = "20180314",
>>  		},
>>  		{
>>  			.matches = {
>> @@ -1439,12 +1451,14 @@ static bool ahci_broken_lpm(struct pci_dev *pdev)
>>  				DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad W541"),
>>  			},
>>  			/*
>> -			 * Note date based on release notes, 2.35 has been
>> -			 * reported to be good, but I've been unable to get
>> -			 * a hold of the reporter to get the DMI BIOS date.
>> -			 * TODO: fix this.
>> +			 * Note: according to release notes, version 2.35 has
>> +			 * working LPM, but we do not have the DMI BIOS date for
>> +			 * this version, so the date, 20180310, is based on the
>> +			 * release notes. Mark any DMI BIOS date before that as
>> +			 * broken.
>> +			 * TODO: find with date with DMI BIOS date.
>>  			 */
>> -			.driver_data = "20180310", /* 2.35 */
>> +			.driver_data = "20180309",
> 
> This reminds me that I did eventually got the actual BIOS date from
> the reporter. After some digging I managed to find the email.
> 
> The first known working BIOS has a BIOS build date of 04/09/2018 so that
> would become "20180409" before your patch / "20180408" after your patch.
> 
> I guess you may want to add a prep patch before the rest of this
> series before this patch to make things a bit cleaner.

Quick followup on this, the original "20180310" was picked to be
one day older then the release-date (which is always after
the build-date) of the known broken 2.34 version.

Here are the release-dates from the release-notes:

https://download.lenovo.com/pccbbs/mobiles/gnuj39us.txt
 
  2.42  (GNUJ39US)  2.42  (GNET94WW)      1.15  (GMHT30WW)    01    2021/06/10
  2.41  (GNUJ38US)  2.41  (GNET93WW)      1.15  (GMHT30WW)    01    2020/05/11
  2.40  (GNUJ37US)  2.40  (GNET92WW)      1.15  (GMHT30WW)    01    2019/09/12
  2.39  (GNUJ36US)  2.39  (GNET91WW)      1.14  (GMHT29WW)    01    2019/06/05
  2.38  (GNUJ35US)  2.38  (GNET90WW)      1.14  (GMHT29WW)    01    2019/03/29
  2.37  (GNUJ34US)  2.37  (GNET89WW)      1.14  (GMHT29WW)    01    2018/11/30
  2.36  (GNUJ33US)  2.36  (GNET88WW)      1.14  (GMHT29WW)    01    2018/06/21
  2.35  (GNUJ32US)  2.35  (GNET87WW)      1.14  (GMHT29WW)    01    2018/04/16
  2.34  (GNUJ31US)  2.34  (GNET86WW)      1.14  (GMHT29WW)    01    2018/03/09
  2.33  (GNUJ30US)  2.33  (GNET85WW)      1.14  (GMHT29WW)    01    2017/12/20
  2.32  (GNUJ29US)  2.32  (GNET84WW)      1.14  (GMHT29WW)    01    2017/09/21
  2.31  (GNUJ28US)  2.31  (GNET83WW)      1.14  (GMHT29WW)    01    2017/05/11
  2.30  (GNUJ27US)  2.30  (GNET82WW)      1.14  (GMHT29WW)    01    2017/04/07

As you can see the known working 2.35 was released at 2018/04/16
so just a few days after its build date of 2018/04/09 .

Regards,
 
Hans



>>  		},
>>  		{ }	/* terminate list */
>>  	};
>> @@ -1458,7 +1472,7 @@ static bool ahci_broken_lpm(struct pci_dev *pdev)
>>  	dmi_get_date(DMI_BIOS_DATE, &year, &month, &date);
>>  	snprintf(buf, sizeof(buf), "%04d%02d%02d", year, month, date);
>>  
>> -	return strcmp(buf, dmi->driver_data) < 0;
>> +	return strcmp(buf, dmi->driver_data) <= 0;
>>  }
>>  
>>  static bool ahci_broken_online(struct pci_dev *pdev)
>