Re: [RFC PATCH 4/6] mmc: tmio: enforce retune after runtime suspend

From: "Niklas Söderlund" <niklas.soderlund@ragnatech.se>
To: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-mmc@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Subject: Re: [RFC PATCH 4/6] mmc: tmio: enforce retune after runtime suspend
Date: Tue, 11 Feb 2020 00:53:54 +0100	[thread overview]
Message-ID: <20200210235354.GD2443363@oden.dyn.berto.se> (raw)
In-Reply-To: <20200129203709.30493-5-wsa+renesas@sang-engineering.com>

Hi Wolfram,

Thanks for your patch.

On 2020-01-29 21:37:07 +0100, Wolfram Sang wrote:
> Currently, select_tuning() is called after RPM resume. But
> select_tuning() needs some additional function calls to work correctly.
> Instead of reimplementing the whole postprocessing, just enforce
> retuning.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
> 
> I couldn't trigger RPM suspend even with debug code. Shimoda-san said
> it should only occur with removed cards which is not so easy with
> soldered eMMC. For those cases, I think the aproach taken here is fine.
> Needs more discussion, though, to make sure...

I really like the change so I really wanted to provoke a suspend to be 
able to provide a tested by tag, but I have so far been unable to do so 
:-(

> 
>  drivers/mmc/host/renesas_sdhi_core.c | 1 -
>  drivers/mmc/host/tmio_mmc.h          | 1 -
>  drivers/mmc/host/tmio_mmc_core.c     | 8 +-------
>  3 files changed, 1 insertion(+), 9 deletions(-)
> 
> diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
> index 24ee8ac1fe21..0c9e5e010bda 100644
> --- a/drivers/mmc/host/renesas_sdhi_core.c
> +++ b/drivers/mmc/host/renesas_sdhi_core.c
> @@ -898,7 +898,6 @@ int renesas_sdhi_probe(struct platform_device *pdev,
>  			dev_warn(&host->pdev->dev, "Unknown clock rate for tuning\n");
>  
>  		host->execute_tuning = renesas_sdhi_execute_tuning;
> -		host->select_tuning = renesas_sdhi_select_tuning;
>  		host->check_retune = renesas_sdhi_check_scc_error;
>  		host->prepare_hs400_tuning =
>  			renesas_sdhi_prepare_hs400_tuning;
> diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
> index bdb9973981ff..b6fffd3d2650 100644
> --- a/drivers/mmc/host/tmio_mmc.h
> +++ b/drivers/mmc/host/tmio_mmc.h
> @@ -183,7 +183,6 @@ struct tmio_mmc_host {
>  	 * and mandatory for SDR104.
>  	 */
>  	int (*execute_tuning)(struct tmio_mmc_host *host, u32 opcode);
> -	int (*select_tuning)(struct tmio_mmc_host *host);
>  
>  	/* Tuning values: 1 for success, 0 for failure */
>  	DECLARE_BITMAP(taps, BITS_PER_BYTE * sizeof(long));
> diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c
> index 3cacb516a66e..aeafa1c68ce2 100644
> --- a/drivers/mmc/host/tmio_mmc_core.c
> +++ b/drivers/mmc/host/tmio_mmc_core.c
> @@ -1302,11 +1302,6 @@ int tmio_mmc_host_runtime_suspend(struct device *dev)
>  }
>  EXPORT_SYMBOL_GPL(tmio_mmc_host_runtime_suspend);
>  
> -static bool tmio_mmc_can_retune(struct tmio_mmc_host *host)
> -{
> -	return host->tap_num && mmc_can_retune(host->mmc);
> -}
> -
>  int tmio_mmc_host_runtime_resume(struct device *dev)
>  {
>  	struct tmio_mmc_host *host = dev_get_drvdata(dev);
> @@ -1323,8 +1318,7 @@ int tmio_mmc_host_runtime_resume(struct device *dev)
>  
>  	tmio_mmc_enable_dma(host, true);
>  
> -	if (tmio_mmc_can_retune(host) && host->select_tuning(host))
> -		dev_warn(&host->pdev->dev, "Tuning selection failed\n");
> +	mmc_retune_needed(host->mmc);
>  
>  	return 0;
>  }
> -- 
> 2.20.1
> 

-- 
Regards,
Niklas Söderlund