[PATCH] ata: libata-core: Add ATA_HORKAGE_NOLPM for Crucial CT240BX500SSD1

[PATCH] ata: libata-core: Add ATA_HORKAGE_NOLPM for Crucial CT240BX500SSD1

[Niklas Cassel]

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 |
-- 
2.45.1

Re: [PATCH] ata: libata-core: Add ATA_HORKAGE_NOLPM for Crucial CT240BX500SSD1

[Damien Le Moal]

On 5/31/24 6:28 AM, Niklas Cassel wrote:
> 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>

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH] ata: libata-core: Add ATA_HORKAGE_NOLPM for Crucial CT240BX500SSD1

[Mika Westerberg]

On Thu, May 30, 2024 at 11:28:17PM +0200, Niklas Cassel wrote:
> 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>

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Re: [PATCH] ata: libata-core: Add ATA_HORKAGE_NOLPM for Crucial CT240BX500SSD1

[Niklas Cassel]

On Thu, 30 May 2024 23:28:17 +0200, Niklas Cassel wrote:
> 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.
> 
> [...]

Applied, thanks!

[1/1] ata: libata-core: Add ATA_HORKAGE_NOLPM for Crucial CT240BX500SSD1
      commit: 86aaa7e9d641c1ad1035ed2df88b8d0b48c86b30

Best regards,
-- 
Niklas Cassel <cassel@kernel.org>