From 24e0e61db3cb86a66824531989f1df80e0939f26 Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Mon, 4 Sep 2023 22:42:56 +0200 Subject: ata: libata: disallow dev-initiated LPM transitions to unsupported states MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In AHCI 1.3.1, the register description for CAP.SSC: "When cleared to ‘0’, software must not allow the HBA to initiate transitions to the Slumber state via agressive link power management nor the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port must be programmed to disallow device initiated Slumber requests." In AHCI 1.3.1, the register description for CAP.PSC: "When cleared to ‘0’, software must not allow the HBA to initiate transitions to the Partial state via agressive link power management nor the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port must be programmed to disallow device initiated Partial requests." Ensure that we always set the corresponding bits in PxSCTL.IPM, such that a device is not allowed to initiate transitions to power states which are unsupported by the HBA. DevSleep is always initiated by the HBA, however, for completeness, set the corresponding bit in PxSCTL.IPM such that agressive link power management cannot transition to DevSleep if DevSleep is not supported. sata_link_scr_lpm() is used by libahci, ata_piix and libata-pmp. However, only libahci has the ability to read the CAP/CAP2 register to see if these features are supported. Therefore, in order to not introduce any regressions on ata_piix or libata-pmp, create flags that indicate that the respective feature is NOT supported. This way, the behavior for ata_piix and libata-pmp should remain unchanged. This change is based on a patch originally submitted by Runa Guo-oc. Signed-off-by: Niklas Cassel Fixes: 1152b2617a6e ("libata: implement sata_link_scr_lpm() and make ata_dev_set_feature() global") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal --- include/linux/libata.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/libata.h b/include/linux/libata.h index 52d58b13e5ee..bf4913f4d7ac 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -222,6 +222,10 @@ enum { ATA_HOST_PARALLEL_SCAN = (1 << 2), /* Ports on this host can be scanned in parallel */ ATA_HOST_IGNORE_ATA = (1 << 3), /* Ignore ATA devices on this host. */ + ATA_HOST_NO_PART = (1 << 4), /* Host does not support partial */ + ATA_HOST_NO_SSC = (1 << 5), /* Host does not support slumber */ + ATA_HOST_NO_DEVSLP = (1 << 6), /* Host does not support devslp */ + /* bits 24:31 of host->flags are reserved for LLD specific flags */ /* various lengths of time */ -- cgit v1.2.3-58-ga151