| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <w3si5lpps5nzpyxjulxynl3fxwobtbnfsqwau6et5s2pkgehub@vcmkdaevbf5w>
Date: Tue, 18 Mar 2025 14:46:13 -0500
From: Bjorn Andersson <andersson@...nel.org>
To: Nitin Rawat <quic_nitirawa@...cinc.com>
Cc: vkoul@...nel.org, kishon@...nel.org, manivannan.sadhasivam@...aro.org,
James.Bottomley@...senpartnership.com, martin.petersen@...cle.com, konrad.dybcio@....qualcomm.com,
quic_rdwivedi@...cinc.com, linux-arm-msm@...r.kernel.org, linux-phy@...ts.infradead.org,
linux-kernel@...r.kernel.org, linux-scsi@...r.kernel.org
Subject: Re: [PATCH V2 3/6] phy: qcom-qmp-ufs: Refactor UFS PHY reset
On Tue, Mar 18, 2025 at 08:19:41PM +0530, Nitin Rawat wrote:
> Refactor the UFS PHY reset handling to parse the reset logic only once
> during probe, instead of every resume.
>
This looks very reasonable! But it would be preferred to see the commit
messages following the what format outlines in
https://docs.kernel.org/process/submitting-patches.html#describe-your-changes
with a clear problem description followed by a description of the
technical solution.
> Move the UFS PHY reset parsing logic from qmp_phy_power_on to
> qmp_ufs_probe to avoid unnecessary parsing during resume.
Please add ()-suffix to function names in your commit messages.
Also, this series moves things around a lot, can you confirm that UFS is
working inbetween each one of this patches, so that the branch is
bisectable when this is being picked up?
>
> Co-developed-by: Ram Kumar Dwivedi <quic_rdwivedi@...cinc.com>
> Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@...cinc.com>
> Signed-off-by: Nitin Rawat <quic_nitirawa@...cinc.com>
> ---
> drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 104 ++++++++++++------------
> 1 file changed, 50 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> index 0089ee80f852..3a80c2c110d2 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-ufs.c
> @@ -1757,32 +1757,6 @@ static void qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg
> qmp_ufs_init_all(qmp, &cfg->tbls_hs_b);
> }
>
> -static int qmp_ufs_com_init(struct qmp_ufs *qmp)
> -{
> - const struct qmp_phy_cfg *cfg = qmp->cfg;
> - void __iomem *pcs = qmp->pcs;
> - int ret;
> -
> - ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> - if (ret) {
> - dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
> - return ret;
> - }
> -
> - ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
> - if (ret)
> - goto err_disable_regulators;
> -
> - qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
> -
> - return 0;
> -
> -err_disable_regulators:
> - regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> -
> - return ret;
> -}
> -
> static int qmp_ufs_com_exit(struct qmp_ufs *qmp)
> {
> const struct qmp_phy_cfg *cfg = qmp->cfg;
> @@ -1800,41 +1774,27 @@ static int qmp_ufs_power_on(struct phy *phy)
> {
> struct qmp_ufs *qmp = phy_get_drvdata(phy);
> const struct qmp_phy_cfg *cfg = qmp->cfg;
> + void __iomem *pcs = qmp->pcs;
This is only used once, perhaps not worth a local variable to save 5
characters on that line?
> int ret;
> - dev_vdbg(qmp->dev, "Initializing QMP phy\n");
> -
> - if (cfg->no_pcs_sw_reset) {
> - /*
> - * Get UFS reset, which is delayed until now to avoid a
> - * circular dependency where UFS needs its PHY, but the PHY
> - * needs this UFS reset.
> - */
> - if (!qmp->ufs_reset) {
> - qmp->ufs_reset =
> - devm_reset_control_get_exclusive(qmp->dev,
> - "ufsphy");
> -
> - if (IS_ERR(qmp->ufs_reset)) {
> - ret = PTR_ERR(qmp->ufs_reset);
> - dev_err(qmp->dev,
> - "failed to get UFS reset: %d\n",
> - ret);
> -
> - qmp->ufs_reset = NULL;
> - return ret;
> - }
> - }
>
> - ret = reset_control_assert(qmp->ufs_reset);
> - if (ret)
> - return ret;
> + ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> + if (ret) {
> + dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
regulator_bulk_enable() will already have printed a more useful error
message, letting you know which of the vregs[] it was that failed to
enable.
> + return ret;
> }
>
> - ret = qmp_ufs_com_init(qmp);
> + ret = clk_bulk_prepare_enable(qmp->num_clks, qmp->clks);
> if (ret)
> - return ret;
> + goto err_disable_regulators;
> +
> + qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
>
> return 0;
> +
> +err_disable_regulators:
> + regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
> +
> + return ret;
> }
>
> static int qmp_ufs_phy_calibrate(struct phy *phy)
> @@ -1846,6 +1806,10 @@ static int qmp_ufs_phy_calibrate(struct phy *phy)
> unsigned int val;
> int ret;
>
> + ret = reset_control_assert(qmp->ufs_reset);
> + if (ret)
> + return ret;
> +
> qmp_ufs_init_registers(qmp, cfg);
>
> ret = reset_control_deassert(qmp->ufs_reset);
> @@ -2088,6 +2052,34 @@ static int qmp_ufs_parse_dt(struct qmp_ufs *qmp)
> return 0;
> }
>
> +static int qmp_ufs_get_phy_reset(struct qmp_ufs *qmp)
> +{
> + const struct qmp_phy_cfg *cfg = qmp->cfg;
> + int ret;
> +
> + if (!cfg->no_pcs_sw_reset)
> + return 0;
> +
> + /*
> + * Get UFS reset, which is delayed until now to avoid a
> + * circular dependency where UFS needs its PHY, but the PHY
> + * needs this UFS reset.
This is invoked only once, from qcom_ufs_probe(), so it doesn't seem
accurate anymore. How come this is no longer needed? Please describe
what changed int he commit message.
> + */
> + if (!qmp->ufs_reset) {
> + qmp->ufs_reset =
> + devm_reset_control_get_exclusive(qmp->dev, "ufsphy");
The line break here is really weird, are you sure checkpatch --strict
didn't complain about this one?
> +
> + if (IS_ERR(qmp->ufs_reset)) {
> + ret = PTR_ERR(qmp->ufs_reset);
> + dev_err(qmp->dev, "failed to get PHY reset: %d\n", ret);
return dev_err_probe(qmp->dev, PTR_ERR(qmp->ufs_reset), "failed to...: %pe\n", qmp->ufs_reset);
While being more succinct, it also stores the reason for failing the
probe so that you can find it in /sys/kernel/debug/devices_deferred
> + qmp->ufs_reset = NULL;
Use a local variable if you're worried about someone accessing the stale
error code after returning here.
Regards,
Bjorn
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> static int qmp_ufs_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> @@ -2114,6 +2106,10 @@ static int qmp_ufs_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + ret = qmp_ufs_get_phy_reset(qmp);
> + if (ret)
> + return ret;
> +
> /* Check for legacy binding with child node. */
> np = of_get_next_available_child(dev->of_node, NULL);
> if (np) {
> --
> 2.48.1
>
>
Powered by blists - more mailing lists