Re: [RFC PATCH] phy: qcom: ipq4019-usb: Propagate reset operation failures

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 8/28/26 11:18 AM, Pengpeng Hou wrote:
> The IPQ4019 USB PHY power operations ignore reset assertion and
> deassertion failures.  Their callers can therefore publish a PHY power
> transition after the reset controller rejected part of it.
> 
> Propagate each reset error and restore the reset that was changed
> earlier in the same HS transition where possible.  This is an RFC
> because a failed reset operation can leave hardware state uncertain;
> feedback is requested on whether the proposed best-effort rollback
> matches these PHYs.

[...]

> 
> The issue was identified via static analysis and manually reviewed.
> 
> Assisted-by: LLM
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
> ---
>  drivers/phy/qualcomm/phy-qcom-ipq4019-usb.c | 46 ++++++++++++++++-----
>  1 file changed, 36 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-ipq4019-usb.c b/drivers/phy/qualcomm/phy-qcom-ipq4019-usb.c
> index da6f290af722..8c1834cd6a8e 100644
> --- a/drivers/phy/qualcomm/phy-qcom-ipq4019-usb.c
> +++ b/drivers/phy/qualcomm/phy-qcom-ipq4019-usb.c
> @@ -30,7 +30,12 @@ static int ipq4019_ss_phy_power_off(struct phy *_phy)
>  {
>  	struct ipq4019_usb_phy *phy = phy_get_drvdata(_phy);
>  
> -	reset_control_assert(phy->por_rst);
> +	int ret;

Please don't leave the blank lines above 'int ret'

[...]

> @@ -69,14 +86,23 @@ static int ipq4019_hs_phy_power_on(struct phy *_phy)
>  {
>  	struct ipq4019_usb_phy *phy = phy_get_drvdata(_phy);
>  
> -	ipq4019_hs_phy_power_off(_phy);
> +	int ret;
> +
> +	ret = ipq4019_hs_phy_power_off(_phy);
> +	if (ret)
> +		return ret;
> +
> +	ret = reset_control_deassert(phy->srif_rst);
> +	if (ret)
> +		return ret;
>  
> -	reset_control_deassert(phy->srif_rst);
>  	msleep(10);
>  
> -	reset_control_deassert(phy->por_rst);
> +	ret = reset_control_deassert(phy->por_rst);
> +	if (ret)
> +		reset_control_assert(phy->srif_rst);

This return value is silently ignored

Konrad

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