Hi,
On 26-May-25 16:03, Niklas Cassel wrote:
> A user has bisected a regression which causes graphical corruptions on his
> screen to commit 7627a0edef54 ("ata: ahci: Drop low power policy board
> type").
>
> Simply reverting commit 7627a0edef54 ("ata: ahci: Drop low power policy
> board type") makes the graphical corruptions on his screen to go away.
> (Note: there are no visible messages in dmesg that indicates a problem
> with AHCI.)
>
> The user also reports that the problem occurs regardless if there is an
> HDD or an SSD connected via AHCI, so the problem is not device related.
>
> The devices also work fine on other motherboards, so it seems specific to
> the ASUSPRO-D840SA motherboard.
>
> While enabling low power modes for AHCI is not supposed to affect
> completely unrelated hardware, like a graphics card, it does however
> allow the system to enter deeper PC-states, which could expose ACPI issues
> that were previously not visible (because the system never entered these
> lower power states before).
>
> There are previous examples where enabling LPM exposed serious BIOS/ACPI
> bugs, see e.g. commit 240630e61870 ("ahci: Disable LPM on Lenovo 50 series
> laptops with a too old BIOS").
>
> Since there hasn't been any BIOS update in years for the ASUSPRO-D840SA
> motherboard, disable LPM for this board, in order to avoid entering lower
> PC-states, which triggers graphical corruptions.
>
> Reported-by: Andy Yang <andyybtc79@xxxxxxxxx>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220111
> Fixes: 7627a0edef54 ("ata: ahci: Drop low power policy board type")
> Signed-off-by: Niklas Cassel <cassel@xxxxxxxxxx>
Thanks, patch looks good to me:
Reviewed-by: Hans de Goede <hansg@xxxxxxxxxx>
Regards,
Hans
> ---
> drivers/ata/ahci.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
> index 163ac909bd06..03f24bff040c 100644
> --- a/drivers/ata/ahci.c
> +++ b/drivers/ata/ahci.c
> @@ -1411,7 +1411,10 @@ 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 */
> + /*
> + * Various Lenovo 50 series and some ASUS boards have LPM issues
> + * with older BIOS versions.
> + */
> {
> .matches = {
> DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> @@ -1446,6 +1449,13 @@ static bool ahci_broken_lpm(struct pci_dev *pdev)
> */
> .driver_data = "20180310", /* 2.35 */
> },
> + {
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
> + DMI_MATCH(DMI_PRODUCT_VERSION, "ASUSPRO D840MB_M840SA/D840MB"),
> + },
> + .driver_data = "20230208", /* 320 */
> + },
> { } /* terminate list */
> };
> const struct dmi_system_id *dmi = dmi_first_match(sysids);
