linux-kernel - Re: [PATCH 1/4] phy: qcom-qmp: Increase the phy init timeout

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Message-ID: <20191220020835.GK448416@yoga>
Date:   Thu, 19 Dec 2019 18:08:35 -0800
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Vinod Koul <vkoul@...nel.org>
Cc:     Kishon Vijay Abraham I <kishon@...com>,
        linux-arm-msm@...r.kernel.org, Andy Gross <agross@...nel.org>,
        Can Guo <cang@...eaurora.org>,
        Jeffrey Hugo <jeffrey.l.hugo@...il.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/4] phy: qcom-qmp: Increase the phy init timeout

On Thu 19 Dec 07:04 PST 2019, Vinod Koul wrote:

> If we do full reset of the phy, it seems to take a couple of ms to come
> up on my system so increase the timeout to 10ms.
> 
> This was found by full reset addition by commit 870b1279c7a0
> ("scsi: ufs-qcom: Add reset control support for host controller") and
> fixes the regression to platforms by this commit.
> 
> Suggested-by: Can Guo <cang@...eaurora.org>
> Signed-off-by: Vinod Koul <vkoul@...nel.org>

This does look familiar...

https://lore.kernel.org/linux-arm-msm/20191107000917.1092409-3-bjorn.andersson@linaro.org/

> ---
>  drivers/phy/qualcomm/phy-qcom-qmp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
> index 091e20303a14..c2e800a3825a 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -66,7 +66,7 @@
>  /* QPHY_V3_PCS_MISC_CLAMP_ENABLE register bits */
>  #define CLAMP_EN				BIT(0) /* enables i/o clamp_n */
>  
> -#define PHY_INIT_COMPLETE_TIMEOUT		1000
> +#define PHY_INIT_COMPLETE_TIMEOUT		100000

100ms seems a little bit excessive, and we do end up waiting this long
when we have PCIe links without an attached device...

Do you need >10ms or could we just have my patch merged?

Regards,
Bjorn

>  #define POWER_DOWN_DELAY_US_MIN			10
>  #define POWER_DOWN_DELAY_US_MAX			11
>  
> -- 
> 2.23.0
>