Re: [REGRESSION][BISECTED] BU40N Blu-Ray drive broken since 7627a0edef54

Damien Le Moal
2025-01-10T09:24:45Z

On 2025/01/10 18:04, Christian Heusel wrote:
> Hello everyone,
>
> we have recently received a report by a user in the Arch Linux Forums
> user that their Blue Ray player, a HL-DT-ST BD-RE BU40N stopped working
> somewhere since kernel version v6.8.0. We have then bisected the issue
> together with them within the mainline kernel sources to the following
> commit that changes the default power policy:
>
> 7627a0edef54 ("ata: ahci: Drop low power policy board type")
>
> The user reports that adding "ahci.mobile_lpm_policy=1" as a kernel
> parameter fixes the issue for them.
>
> Additionally fellow forum user @loqs came up with a quirk patch, that
> sadly was reported to not work:
>
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index c085dd8..ef01ccd 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -4118,6 +4118,9 @@ static const struct ata_dev_quirks_entry __ata_dev_quirks[] = {
> { "SAMSUNG MZ7TD256HAFV-000L9", NULL, ATA_QUIRK_NOLPM },
> { "SAMSUNG MZ7TE512HMHP-000L1", "EXT06L0Q", ATA_QUIRK_NOLPM },
>
> + /* Hitachi-LG Data Storage models with LPM issues */
> + { "HL-DT-ST BD-RE BU40N", NULL, ATA_QUIRK_NOLPM },

Looks like "BU40N" may be the FW rev ? If we can get a dmesg ourput of the
failing case, we should be able to sort out this. Likely it is a bad string
reference here.

> +
> /* devices that don't properly handle queued TRIM commands */
> { "Micron_M500IT_*", "MU01", ATA_QUIRK_NO_NCQ_TRIM |
> ATA_QUIRK_ZERO_AFTER_TRIM },
>
> So if anyone has feedback on why the patch does not work or any
> alternative ideas for a solution that would be highly appreciated!
>
> Cheers,
> gromit
>
> [0]: https://bbs.archlinux.org/viewtopic.php?id=302334
>
> ---
>
> #regzbot introduced: 7627a0edef54
> #regzbot link: https://bbs.archlinux.org/viewtopic.php?id=302334
> #regzbot title: ata: ahci: Blue Ray player broken since power policy change

--
Damien Le Moal
Western Digital Research