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@xxxxxxxxxx>
> ---
> 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 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.
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)
