| From a697a92094f971e92f2444ab7ae6b7c3511fe8cc Mon Sep 17 00:00:00 2001 |
| From: Stanley Chu <stanley.chu@mediatek.com> |
| Date: Thu, 28 Mar 2019 17:16:25 +0800 |
| Subject: scsi: ufs: Fix regulator load and icc-level configuration |
| |
| [ Upstream commit 0487fff76632ec023d394a05b82e87a971db8c03 ] |
| |
| Currently if a regulator has "<name>-fixed-regulator" property in device |
| tree, it will skip current limit initialization. This lead to a zero |
| "max_uA" value in struct ufs_vreg. |
| |
| However, "regulator_set_load" operation shall be required on regulators |
| which have valid current limits, otherwise a zero "max_uA" set by |
| "regulator_set_load" may cause unexpected behavior when this regulator is |
| enabled or set as high power mode. |
| |
| Similarly, in device's icc_level configuration flow, the target icc_level |
| shall be updated if regulator also has valid current limit, otherwise a |
| wrong icc_level will be calculated by zero "max_uA" and thus causes |
| unexpected results after it is written to device. |
| |
| Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> |
| Reviewed-by: Avri Altman <avri.altman@wdc.com> |
| Acked-by: Alim Akhtar <alim.akhtar@samsung.com> |
| Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/scsi/ufs/ufshcd.c | 15 ++++++++++++--- |
| 1 file changed, 12 insertions(+), 3 deletions(-) |
| |
| diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c |
| index e040f9dd9ff32..58e0bd1dac9b4 100644 |
| --- a/drivers/scsi/ufs/ufshcd.c |
| +++ b/drivers/scsi/ufs/ufshcd.c |
| @@ -6294,19 +6294,19 @@ static u32 ufshcd_find_max_sup_active_icc_level(struct ufs_hba *hba, |
| goto out; |
| } |
| |
| - if (hba->vreg_info.vcc) |
| + if (hba->vreg_info.vcc && hba->vreg_info.vcc->max_uA) |
| icc_level = ufshcd_get_max_icc_level( |
| hba->vreg_info.vcc->max_uA, |
| POWER_DESC_MAX_ACTV_ICC_LVLS - 1, |
| &desc_buf[PWR_DESC_ACTIVE_LVLS_VCC_0]); |
| |
| - if (hba->vreg_info.vccq) |
| + if (hba->vreg_info.vccq && hba->vreg_info.vccq->max_uA) |
| icc_level = ufshcd_get_max_icc_level( |
| hba->vreg_info.vccq->max_uA, |
| icc_level, |
| &desc_buf[PWR_DESC_ACTIVE_LVLS_VCCQ_0]); |
| |
| - if (hba->vreg_info.vccq2) |
| + if (hba->vreg_info.vccq2 && hba->vreg_info.vccq2->max_uA) |
| icc_level = ufshcd_get_max_icc_level( |
| hba->vreg_info.vccq2->max_uA, |
| icc_level, |
| @@ -7004,6 +7004,15 @@ static int ufshcd_config_vreg_load(struct device *dev, struct ufs_vreg *vreg, |
| if (!vreg) |
| return 0; |
| |
| + /* |
| + * "set_load" operation shall be required on those regulators |
| + * which specifically configured current limitation. Otherwise |
| + * zero max_uA may cause unexpected behavior when regulator is |
| + * enabled or set as high power mode. |
| + */ |
| + if (!vreg->max_uA) |
| + return 0; |
| + |
| ret = regulator_set_load(vreg->reg, ua); |
| if (ret < 0) { |
| dev_err(dev, "%s: %s set load (ua=%d) failed, err=%d\n", |
| -- |
| 2.20.1 |
| |
