linux-kernel - Re: [PATCH v3 06/20] firmware: use helpers for setting up a temporary cache timeout

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Date:   Wed, 14 Mar 2018 19:55:14 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     "Luis R. Rodriguez" <mcgrof@...nel.org>
Cc:     akpm@...ux-foundation.org, cantabile.desu@...il.com,
        kubakici@...pl, linux-wireless@...r.kernel.org,
        keescook@...omium.org, shuah@...nel.org, mfuzzey@...keon.com,
        zohar@...ux.vnet.ibm.com, dhowells@...hat.com,
        pali.rohar@...il.com, tiwai@...e.de, arend.vanspriel@...adcom.com,
        zajec5@...il.com, nbroeking@...com, markivx@...eaurora.org,
        broonie@...nel.org, dmitry.torokhov@...il.com, dwmw2@...radead.org,
        torvalds@...ux-foundation.org, Abhay_Salunke@...l.com,
        bjorn.andersson@...aro.org, jewalt@...innovations.com,
        oneukum@...e.com, ast@...com, andresx7@...il.com,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH v3 06/20] firmware: use helpers for setting up a
 temporary cache timeout

On Sat, Mar 10, 2018 at 06:14:47AM -0800, Luis R. Rodriguez wrote:
> We only use the timeout for the firmware fallback mechanism
> except for trying to set the timeout during the cache setup
> for resume/suspend. For those cases, setting the timeout should
> be a no-op, so just reflect this in code by adding helpers for it.
> 
> This change introduces no functional changes.
> 
> Acked-by: Kees Cook <keescook@...omium.org>
> Signed-off-by: Luis R. Rodriguez <mcgrof@...nel.org>
> ---
>  drivers/base/firmware_loader.c | 49 ++++++++++++++++++++++++++----------------
>  1 file changed, 30 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/base/firmware_loader.c b/drivers/base/firmware_loader.c
> index 59dba794ce1a..2d819875348d 100644
> --- a/drivers/base/firmware_loader.c
> +++ b/drivers/base/firmware_loader.c
> @@ -191,13 +191,6 @@ static inline bool fw_is_builtin_firmware(const struct firmware *fw)
>  }
>  #endif
>  
> -static int loading_timeout = 60;	/* In seconds */
> -
> -static inline long firmware_loading_timeout(void)
> -{
> -	return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
> -}
> -
>  static void fw_state_init(struct fw_priv *fw_priv)
>  {
>  	struct fw_state *fw_st = &fw_priv->fw_st;
> @@ -282,6 +275,32 @@ static const struct firmware_fallback_config fw_fallback_config = {
>  	.force_sysfs_fallback = IS_ENABLED(CONFIG_FW_LOADER_USER_HELPER_FALLBACK),
>  };
>  
> +static int old_timeout;
> +static int loading_timeout = 60;	/* In seconds */
> +
> +static inline long firmware_loading_timeout(void)
> +{
> +	return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
> +}
> +
> +/*
> + * use small loading timeout for caching devices' firmware because all these
> + * firmware images have been loaded successfully at lease once, also system is
> + * ready for completing firmware loading now. The maximum size of firmware in
> + * current distributions is about 2M bytes, so 10 secs should be enough.
> + */
> +static void fw_fallback_set_cache_timeout(void)
> +{
> +	old_timeout = loading_timeout;
> +	loading_timeout = 10;
> +}
> +
> +/* Restores the timeout to the value last configured during normal operation */
> +static void fw_fallback_set_default_timeout(void)
> +{
> +	loading_timeout =  old_timeout;

extra space?

Yeah, nit, I know :)