diff options
| author | Bao D. Nguyen <quic_nguyenb@quicinc.com> | 2025-10-13 22:38:16 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2025-10-22 04:22:17 +0300 |
| commit | 4760b639b43c107c8bfccd658478bbb3152fa56f (patch) | |
| tree | 31b8a08dc0deed9cf411245c5ecd603aa1946e49 | |
| parent | f8e82ae65eaf347fb8924a1d9c544da7bcb9f798 (diff) | |
| download | linux-4760b639b43c107c8bfccd658478bbb3152fa56f.tar.xz | |
scsi: ufs: core: Replace hard coded vcc-off delay with a variable
After the UFS device VCC is powered off, all the UFS device
manufacturers require a minimum of 1ms of power-off time before VCC can
be powered on again. This requirement has been verified with all the UFS
device manufacturer's datasheets.
Replace the hard coded 5ms delay with a variable with a default setting
of 2ms to improve the system resume latency. The platform drivers can
override this setting as needed.
Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Link: https://patch.msgid.link/72fa649406a0bf02271575b7d58f22c968aa5d7e.1760383740.git.quic_nguyenb@quicinc.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
| -rw-r--r-- | drivers/ufs/core/ufshcd.c | 10 | ||||
| -rw-r--r-- | include/ufs/ufshcd.h | 2 |
2 files changed, 11 insertions, 1 deletions
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 4ca652c02ac2..516e9e06d3c3 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -9777,7 +9777,8 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) * All UFS devices require delay after VCC power rail is turned-off. */ if (vcc_off && hba->vreg_info.vcc && !hba->vreg_info.vcc->always_on) - usleep_range(5000, 5100); + usleep_range(hba->vcc_off_delay_us, + hba->vcc_off_delay_us + 100); } #ifdef CONFIG_PM @@ -10704,6 +10705,13 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) UFS_SLEEP_PWR_MODE, UIC_LINK_HIBERN8_STATE); + /* + * Most ufs devices require 1ms delay after vcc is powered off before + * it can be powered on again. Set the default to 2ms. The platform + * drivers can override this setting as needed. + */ + hba->vcc_off_delay_us = 2000; + init_completion(&hba->dev_cmd.complete); err = ufshcd_hba_init(hba); diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h index 9425cfd9d00e..752640a3e25f 100644 --- a/include/ufs/ufshcd.h +++ b/include/ufs/ufshcd.h @@ -1117,6 +1117,8 @@ struct ufs_hba { int critical_health_count; atomic_t dev_lvl_exception_count; u64 dev_lvl_exception_id; + + u32 vcc_off_delay_us; }; /** |