Re: [PATCH v3 2/7] mmc: sdhci: add __sdhci_execute_tuning() to header

From: Jisheng Zhang <jszhang@kernel.org>
To: Drew Fustini <dfustini@baylibre.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Guo Ren <guoren@kernel.org>, Fu Wei <wefu@redhat.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Conor Dooley <conor@kernel.org>,
	Robert Nelson <robertcnelson@beagleboard.org>,
	Jason Kridner <jkridner@beagleboard.org>,
	Xi Ruoyao <xry111@xry111.site>, Han Gao <gaohan@iscas.ac.cn>,
	Icenowy Zheng <uwu@icenowy.me>,
	linux-mmc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org
Subject: Re: [PATCH v3 2/7] mmc: sdhci: add __sdhci_execute_tuning() to header
Date: Wed, 25 Oct 2023 23:29:25 +0800	[thread overview]
Message-ID: <ZTk0VcFd3FcXIABW@xhacker> (raw)
In-Reply-To: <20231023-th1520-mmc-v3-2-abc5e7491166@baylibre.com>

On Mon, Oct 23, 2023 at 02:07:03PM -0700, Drew Fustini wrote:
> Expose __sdhci_execute_tuning() so that it can be called from the
> mmc host controller drivers.
> 
> In the sdhci-of-dwcmshc driver, sdhci_dwcmshc_th1520_ops sets
> platform_execute_tuning to th1520_execute_tuning(). That function has

Hi Drew,

Just FYI, my th1520 version patch in my local repo overrides the
mmc_host_ops.execute_tuning as the following:

host->mmc_host_ops.execute_tuning = dwcmshc_execute_tuning;

In dwcmshc_execute_tuning(), I will do some necessary setting then
call sdhci_execute_tuning();

So I don't need to export __sdhci_execute_tuning(). The main reason
is that the __abc symbol is expected to be used internally. However,
I have no big preference. I would leave the decision be made by
mmc maintainers @Ulf @Adrian, can you please comment?

Thanks

> to manipulate phy registers before tuning can be performed. To avoid
> copying the code verbatim from __sdhci_execute_tuning() into
> th1520_execute_tuning(), make it possible for __sdhci_execute_tuning()
> to be called from sdhci-of-dwcmshc.
> 
> Signed-off-by: Drew Fustini <dfustini@baylibre.com>
> ---
>  drivers/mmc/host/sdhci.c | 3 ++-
>  drivers/mmc/host/sdhci.h | 1 +
>  2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index ff41aa56564e..c79f73459915 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2841,7 +2841,7 @@ void sdhci_send_tuning(struct sdhci_host *host, u32 opcode)
>  }
>  EXPORT_SYMBOL_GPL(sdhci_send_tuning);
>  
> -static int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
> +int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
>  {
>  	int i;
>  
> @@ -2879,6 +2879,7 @@ static int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
>  	sdhci_reset_tuning(host);
>  	return -EAGAIN;
>  }
> +EXPORT_SYMBOL_GPL(__sdhci_execute_tuning);
>  
>  int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>  {
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index f219bdea8f28..a20864fc0641 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -793,6 +793,7 @@ void sdhci_set_bus_width(struct sdhci_host *host, int width);
>  void sdhci_reset(struct sdhci_host *host, u8 mask);
>  void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
>  int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
> +int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode);
>  void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);
>  int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
>  				      struct mmc_ios *ios);
> 
> -- 
> 2.34.1
> 