projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 7be860c4 GKH |
1 | From foo@baz Mon Sep 17 12:15:09 CEST 2018 |
| 2 | From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | |
| 3 | Date: Mon, 2 Jul 2018 12:01:53 -0700 | |
| 4 | Subject: ata: libahci: Correct setting of DEVSLP register | |
| 5 | ||
| 6 | From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | |
| 7 | ||
| 8 | [ Upstream commit 2dbb3ec29a6c069035857a2fc4c24e80e5dfe3cc ] | |
| 9 | ||
| 10 | We have seen that on some platforms, SATA device never show any DEVSLP | |
| 11 | residency. This prevent power gating of SATA IP, which prevent system | |
| 12 | to transition to low power mode in systems with SLP_S0 aka modern | |
| 13 | standby systems. The PHY logic is off only in DEVSLP not in slumber. | |
| 14 | Reference: | |
| 15 | https://www.intel.com/content/dam/www/public/us/en/documents/datasheets | |
| 16 | /332995-skylake-i-o-platform-datasheet-volume-1.pdf | |
| 17 | Section 28.7.6.1 | |
| 18 | ||
| 19 | Here driver is trying to do read-modify-write the devslp register. But | |
| 20 | not resetting the bits for which this driver will modify values (DITO, | |
| 21 | MDAT and DETO). So simply reset those bits before updating to new values. | |
| 22 | ||
| 23 | Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | |
| 24 | Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> | |
| 25 | Reviewed-by: Hans de Goede <hdegoede@redhat.com> | |
| 26 | Signed-off-by: Tejun Heo <tj@kernel.org> | |
| 27 | Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> | |
| 28 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 29 | --- | |
| 30 | drivers/ata/libahci.c | 2 ++ | |
| 31 | 1 file changed, 2 insertions(+) | |
| 32 | ||
| 33 | --- a/drivers/ata/libahci.c | |
| 34 | +++ b/drivers/ata/libahci.c | |
| 35 | @@ -2113,6 +2113,8 @@ static void ahci_set_aggressive_devslp(s | |
| 36 | deto = 20; | |
| 37 | } | |
| 38 | ||
| 39 | + /* Make dito, mdat, deto bits to 0s */ | |
| 40 | + devslp &= ~GENMASK_ULL(24, 2); | |
| 41 | devslp |= ((dito << PORT_DEVSLP_DITO_OFFSET) | | |
| 42 | (mdat << PORT_DEVSLP_MDAT_OFFSET) | | |
| 43 | (deto << PORT_DEVSLP_DETO_OFFSET) | |