On Thu, May 31, 2018 at 01:21:07PM +0200, Hans de Goede wrote:
> Commit 184add2ca23c ("libata: Apply NOLPM quirk for SanDisk
> SD7UB3Q*G1001 SSDs") disabled LPM for SanDisk SD7UB3Q*G1001 SSDs.
>
> This has lead to several reports of users of that SSD where LPM
> was working fine and who know have a significantly increased idle
> power consumption on their laptops.
>
> Likely there is another problem on the T450s from the original
> reporter which gets exposed by the uncore reaching deeper sleep
> states (higher PC-states) due to LPM being enabled. The problem as
> reported, a hardfreeze about once a day, already did not sound like
> it would be caused by LPM and the reports of the SSD working fine
> confirm this. The original reporter is ok with dropping the quirk.
>
> A X250 user has reported the same hard freeze problem and for him
> the problem went away after unrelated updates, I suspect some GPU
> driver stack changes fixed things.
>
> TL;DR: The original reporters problem were triggered by LPM but not
> an LPM issue, so drop the quirk for the SSD in question.
As the reporter of the original issue, I agree with Hans's
analysis above, so ACK from me.
Rich.
> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1583207
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Richard W.M. Jones <rjones@xxxxxxxxxx>
> Cc: Lorenzo Dalrio <lorenzo.dalrio@xxxxxxxxx>
> Reported-by: Lorenzo Dalrio <lorenzo.dalrio@xxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> Changes in v2:
> -Rebase on 4.17-rc7
> ---
> drivers/ata/libata-core.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 346b163f6e89..9bfd2f7e4542 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -4557,9 +4557,6 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
> { "SAMSUNG MZMPC128HBFU-000MV", "CXM14M1Q", ATA_HORKAGE_NOLPM, },
> { "SAMSUNG SSD PM830 mSATA *", "CXM13D1Q", ATA_HORKAGE_NOLPM, },
>
> - /* Sandisk devices which are known to not handle LPM well */
> - { "SanDisk SD7UB3Q*G1001", NULL, ATA_HORKAGE_NOLPM, },
> -
> /* devices that don't properly handle queued TRIM commands */
> { "Micron_M500IT_*", "MU01", ATA_HORKAGE_NO_NCQ_TRIM |
> ATA_HORKAGE_ZERO_AFTER_TRIM, },
> --
> 2.17.0
--
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