[PATCH v1 1/2] scsi: ufs: Introduce device quirk "DELAY_AFTER_LPM"
From: Stanley Chu <hidden>
Date: 2020-07-29 05:18:54
Also in:
linux-mediatek, linux-scsi, lkml
Subsystem:
scsi subsystem, the rest · Maintainers:
"James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
Some UFS devices require delay after VCC power rail is turned-off. Introduce a device quirk "DELAY_AFTER_LPM" to add 5ms delays after VCC power-off during suspend flow. Signed-off-by: Andy Teng <redacted> Signed-off-by: Peter Wang <peter.wang@mediatek.com> Signed-off-by: Stanley Chu <redacted> --- drivers/scsi/ufs/ufs_quirks.h | 7 +++++++ drivers/scsi/ufs/ufshcd.c | 11 +++++++++++ 2 files changed, 18 insertions(+)
diff --git a/drivers/scsi/ufs/ufs_quirks.h b/drivers/scsi/ufs/ufs_quirks.h
index 2a0041493e30..07f559ac5883 100644
--- a/drivers/scsi/ufs/ufs_quirks.h
+++ b/drivers/scsi/ufs/ufs_quirks.h@@ -109,4 +109,11 @@ struct ufs_dev_fix { */ #define UFS_DEVICE_QUIRK_SUPPORT_EXTENDED_FEATURES (1 << 10) +/* + * Some UFS devices require delay after VCC power rail is turned-off. + * Enable this quirk to introduce 5ms delays after VCC power-off during + * suspend flow. + */ +#define UFS_DEVICE_QUIRK_DELAY_AFTER_LPM (1 << 11) + #endif /* UFS_QUIRKS_H_ */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index acba2271c5d3..63f4e2f75aa1 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c@@ -8111,6 +8111,8 @@ static int ufshcd_link_state_transition(struct ufs_hba *hba, static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) { + bool vcc_off = false; + /* * It seems some UFS devices may keep drawing more than sleep current * (atleast for 500us) from UFS rails (especially from VCCQ rail).
@@ -8139,13 +8141,22 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba) && !hba->dev_info.is_lu_power_on_wp) { ufshcd_setup_vreg(hba, false); + vcc_off = true; } else if (!ufshcd_is_ufs_dev_active(hba)) { ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); + vcc_off = true; if (!ufshcd_is_link_active(hba)) { ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq); ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2); } } + + /* + * Some UFS devices require delay after VCC power rail is turned-off. + */ + if (vcc_off && hba->vreg_info.vcc && + hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM) + usleep_range(5000, 5100); } static int ufshcd_vreg_set_hpm(struct ufs_hba *hba)
--
2.18.0
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