On 6/12/25 23:17, 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.
Cc: stable@vger.kernel.org Reported-by: Andy Yang andyybtc79@gmail.com 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@kernel.org
Reviewed-by: Damien Le Moal dlemoal@kernel.org