From: Can Guo <cang@codeaurora.org>
To: Ziqi Chen <ziqichen@codeaurora.org>
Cc: asutoshd@codeaurora.org, nguyenb@codeaurora.org,
hongwus@codeaurora.org, rnayak@codeaurora.org,
vinholikatti@gmail.com, jejb@linux.vnet.ibm.com,
martin.petersen@oracle.com, linux-scsi@vger.kernel.org,
kernel-team@android.com, saravanak@google.com,
salyzyn@google.com, Andy Gross <agross@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Alim Akhtar <alim.akhtar@samsung.com>,
Avri Altman <avri.altman@wdc.com>,
"James E.J. Bottomley" <jejb@linux.ibm.com>,
Stanley Chu <stanley.chu@mediatek.com>,
Bean Huo <beanhuo@micron.com>,
Bart Van Assche <bvanassche@acm.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Satya Tangirala <satyat@google.com>,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 1/1] scsi: ufs: Fix ufs power down/on specs violation
Date: Wed, 09 Dec 2020 16:01:16 +0800 [thread overview]
Message-ID: <6105ea481f6a42fb0e5133e442a51549@codeaurora.org> (raw)
In-Reply-To: <1607497774-76579-1-git-send-email-ziqichen@codeaurora.org>
On 2020-12-09 15:09, Ziqi Chen wrote:
> As per specs, e.g, JESD220E chapter 7.2, while powering
> off/on the ufs device, RST_N signal and REF_CLK signal
> should be between VSS(Ground) and VCCQ/VCCQ2.
>
> Power down:
> 1. Assert RST_N low
> 2. Turn-off REF_CLK
> 3. Turn-off VCC
> 4. Turn-off VCCQ/VCCQ2.
> power on:
> 1. Turn-on VCC
> 2. Turn-on VCCQ/VCCQ2
> 3. Turn-On REF_CLK
> 4. Deassert RST_N high.
>
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> ---
> drivers/scsi/ufs/ufs-qcom.c | 14 ++++++++++----
> drivers/scsi/ufs/ufshcd.c | 19 +++++++++----------
> drivers/scsi/ufs/ufshcd.h | 4 ++--
> 3 files changed, 21 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 1e434cc..5ed3a63d 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -582,6 +582,9 @@ static int ufs_qcom_suspend(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
> ufs_qcom_disable_lane_clks(host);
> phy_power_off(phy);
>
> + if (hba->vops && hba->vops->device_reset)
> + hba->vops->device_reset(hba, false);
> +
> } else if (!ufs_qcom_is_link_active(hba)) {
> ufs_qcom_disable_lane_clks(host);
> }
> @@ -1400,10 +1403,11 @@ static void ufs_qcom_dump_dbg_regs(struct
> ufs_hba *hba)
> /**
> * ufs_qcom_device_reset() - toggle the (optional) device reset line
> * @hba: per-adapter instance
> + * @toggle: need pulling up or not
> *
> * Toggles the (optional) reset line to reset the attached device.
> */
> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> +static int ufs_qcom_device_reset(struct ufs_hba *hba, bool toggle)
> {
> struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>
> @@ -1416,10 +1420,12 @@ static int ufs_qcom_device_reset(struct ufs_hba
> *hba)
> * be on the safe side.
> */
> gpiod_set_value_cansleep(host->device_reset, 1);
> - usleep_range(10, 15);
>
> - gpiod_set_value_cansleep(host->device_reset, 0);
> - usleep_range(10, 15);
> + if (toggle) {
> + usleep_range(10, 15);
> + gpiod_set_value_cansleep(host->device_reset, 0);
> + usleep_range(10, 15);
> + }
>
> return 0;
> }
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 92d433d..5ab1c02 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -8633,8 +8633,6 @@ static int ufshcd_suspend(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
> if (ret)
> goto set_dev_active;
>
> - ufshcd_vreg_set_lpm(hba);
> -
> disable_clks:
> /*
> * Call vendor specific suspend callback. As these callbacks may
> access
> @@ -8664,6 +8662,7 @@ static int ufshcd_suspend(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
>
> /* Put the host controller in low power mode if possible */
> ufshcd_hba_vreg_set_lpm(hba);
> + ufshcd_vreg_set_lpm(hba);
> goto out;
>
> set_link_active:
> @@ -8729,18 +8728,18 @@ static int ufshcd_resume(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
> old_link_state = hba->uic_link_state;
>
> ufshcd_hba_vreg_set_hpm(hba);
> + ret = ufshcd_vreg_set_hpm(hba);
> + if (ret)
> + goto out;
> +
> /* Make sure clocks are enabled before accessing controller */
> ret = ufshcd_setup_clocks(hba, true);
> if (ret)
> - goto out;
> + goto disable_vreg;
>
> /* enable the host irq as host controller would be active soon */
> ufshcd_enable_irq(hba);
>
> - ret = ufshcd_vreg_set_hpm(hba);
> - if (ret)
> - goto disable_irq_and_vops_clks;
> -
> /*
> * Call vendor specific resume callback. As these callbacks may
> access
> * vendor specific host controller register space call them when the
> @@ -8748,7 +8747,7 @@ static int ufshcd_resume(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
> */
> ret = ufshcd_vops_resume(hba, pm_op);
> if (ret)
> - goto disable_vreg;
> + goto disable_irq_and_vops_clks;
>
> /* For DeepSleep, the only supported option is to have the link off
> */
> WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) &&
> !ufshcd_is_link_off(hba));
> @@ -8815,8 +8814,6 @@ static int ufshcd_resume(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
> ufshcd_link_state_transition(hba, old_link_state, 0);
> vendor_suspend:
> ufshcd_vops_suspend(hba, pm_op);
> -disable_vreg:
> - ufshcd_vreg_set_lpm(hba);
> disable_irq_and_vops_clks:
> ufshcd_disable_irq(hba);
> if (hba->clk_scaling.is_allowed)
> @@ -8827,6 +8824,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
> trace_ufshcd_clk_gating(dev_name(hba->dev),
> hba->clk_gating.state);
> }
> +disable_vreg:
> + ufshcd_vreg_set_lpm(hba);
> out:
> hba->pm_op_in_progress = 0;
> if (ret)
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 61344c4..47c7dab6 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -323,7 +323,7 @@ struct ufs_hba_variant_ops {
> int (*resume)(struct ufs_hba *, enum ufs_pm_op);
> void (*dbg_register_dump)(struct ufs_hba *hba);
> int (*phy_initialization)(struct ufs_hba *);
> - int (*device_reset)(struct ufs_hba *hba);
> + int (*device_reset)(struct ufs_hba *hba, bool);
> void (*config_scaling_param)(struct ufs_hba *hba,
> struct devfreq_dev_profile *profile,
> void *data);
> @@ -1211,7 +1211,7 @@ static inline void
> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
> static inline void ufshcd_vops_device_reset(struct ufs_hba *hba)
> {
> if (hba->vops && hba->vops->device_reset) {
> - int err = hba->vops->device_reset(hba);
> + int err = hba->vops->device_reset(hba, true);
>
> if (!err)
> ufshcd_set_ufs_dev_active(hba);
Please check Stanley's new change
https://lore.kernel.org/patchwork/patch/1350843/.
You may want to re-name the func ufschd_vops_device_reset() to
ufshcd_vops_toggle_device_reset(sturct ufs_hba *hba, bool up) and
similarly re-name device_reset() to toggle_device_reset(hba, up).
Then in the new func ufshcd_device_reset(), call
ufshcd_vops_toggle_device_reset()
twice, once to toggle up, once to toggle down. In this way, you will be
able to use ufshcd_vops_toggle_device_reset() in ufshcd_suspend().
This is just a rough idea.
Thanks,
Can Guo.
prev parent reply other threads:[~2020-12-09 8:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-09 7:09 [PATCH v1 1/1] scsi: ufs: Fix ufs power down/on specs violation Ziqi Chen
2020-12-09 7:19 ` Can Guo
2020-12-09 7:27 ` Can Guo
2020-12-09 7:46 ` ziqichen
2020-12-09 8:01 ` Can Guo [this message]
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