Commit 7627a0edef54 ("ata: ahci: Drop low power policy board type") dropped the board_ahci_low_power board type, and instead enables LPM if: -The AHCI controller reports that it supports LPM (Partial/Slumber), and -CONFIG_SATA_MOBILE_LPM_POLICY != 0, and -The port is not defined as external in the per port PxCMD register, and -The port is not defined as hotplug capable in the per port PxCMD register.
Partial and Slumber LPM states can either be initiated by HIPM or DIPM.
For HIPM (host initiated power management) to get enabled, both the AHCI controller and the drive have to report that they support HIPM.
For DIPM (device initiated power management) to get enabled, only the drive has to report that it supports DIPM. However, the HBA will reject device requests to enter LPM states which the HBA does not support.
The problem is that Crucial CT240BX500SSD1 drives do not handle low power modes correctly. The problem was most likely not seen before because no one had used this drive with a AHCI controller with LPM enabled.
Add a quirk so that we do not enable LPM for this drive, since we see command timeouts if we do (even though the drive claims to support DIPM).
Fixes: 7627a0edef54 ("ata: ahci: Drop low power policy board type") Cc: stable@vger.kernel.org Reported-by: Aarrayy lp610mh@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218832 Signed-off-by: Niklas Cassel cassel@kernel.org --- On the system reporting this issue, the HBA supports SALP (HIPM) and LPM states Partial and Slumber.
This drive only supports DIPM but not HIPM, however, that should not matter, as a DIPM request from the device still has to be acked by the HBA, and according to AHCI 1.3.1, section 5.3.2.11 P:Idle, if the link layer has negotiated to low power state based on device power management request, the HBA will jump to state PM:LowPower.
In PM:LowPower, the HBA will automatically request to wake the link (exit from Partial/Slumber) when a new command is queued (by writing to PxCI). Thus, there should be no need for host software to request an explicit wakeup (by writing PxCMD.ICC to 1).
Therefore, even with only DIPM supported/enabled, we shouldn't see command timeouts with the current code. Also, only enabling only DIPM (by modifying the AHCI driver) with another drive (which support both DIPM and HIPM), shows no errors. Thus, it seems like the drive is the problem.
drivers/ata/libata-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 4f35aab81a0a..b0ce621fe2a1 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4136,8 +4136,9 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = { { "PIONEER BD-RW BDR-207M", NULL, ATA_HORKAGE_NOLPM }, { "PIONEER BD-RW BDR-205", NULL, ATA_HORKAGE_NOLPM },
- /* Crucial BX100 SSD 500GB has broken LPM support */ + /* Crucial devices with broken LPM support */ { "CT500BX100SSD1", NULL, ATA_HORKAGE_NOLPM }, + { "CT240BX500SSD1", NULL, ATA_HORKAGE_NOLPM },
/* 512GB MX100 with MU01 firmware has both queued TRIM and LPM issues */ { "Crucial_CT512MX100*", "MU01", ATA_HORKAGE_NO_NCQ_TRIM |