linux-kernel - Re: [PATCH] bq27x00: use cached flags

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 19 Feb 2019 10:55:37 -0600
From:   "Andrew F. Davis" <afd@...com>
To:     Arthur Demchenkov <spinal.by@...il.com>
CC:     Pali Rohár <pali.rohar@...il.com>,
        Sebastian Reichel <sre@...nel.org>, <linux-pm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] bq27x00: use cached flags

On 2/18/19 12:59 AM, Arthur Demchenkov wrote:
> The flags were just read by bq27xxx_battery_update(),
> no need to read them again.
> 
> Signed-off-by: Arthur Demchenkov <spinal.by@...il.com>
> ---

Nothing obviously wrong with this patch so:

Reviewed-by: Andrew F. Davis <afd@...com>

At this point we have W1 regmap and so we now have everything we should
need to convert this driver over to regmap. Then the caching comes for
free and a lot of checks and such can be dropped.

Thanks,
Andrew

>  drivers/power/supply/bq27xxx_battery.c | 20 ++++----------------
>  1 file changed, 4 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/power/supply/bq27xxx_battery.c b/drivers/power/supply/bq27xxx_battery.c
> index 6dbbe95844a3..29b3a4056865 100644
> --- a/drivers/power/supply/bq27xxx_battery.c
> +++ b/drivers/power/supply/bq27xxx_battery.c
> @@ -1555,27 +1555,14 @@ static bool bq27xxx_battery_dead(struct bq27xxx_device_info *di, u16 flags)
>  		return flags & (BQ27XXX_FLAG_SOC1 | BQ27XXX_FLAG_SOCF);
>  }
>  
> -/*
> - * Read flag register.
> - * Return < 0 if something fails.
> - */
>  static int bq27xxx_battery_read_health(struct bq27xxx_device_info *di)
>  {
> -	int flags;
> -	bool has_singe_flag = di->opts & BQ27XXX_O_ZERO;
> -
> -	flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, has_singe_flag);
> -	if (flags < 0) {
> -		dev_err(di->dev, "error reading flag register:%d\n", flags);
> -		return flags;
> -	}
> -
>  	/* Unlikely but important to return first */
> -	if (unlikely(bq27xxx_battery_overtemp(di, flags)))
> +	if (unlikely(bq27xxx_battery_overtemp(di, di->cache.flags)))
>  		return POWER_SUPPLY_HEALTH_OVERHEAT;
> -	if (unlikely(bq27xxx_battery_undertemp(di, flags)))
> +	if (unlikely(bq27xxx_battery_undertemp(di, di->cache.flags)))
>  		return POWER_SUPPLY_HEALTH_COLD;
> -	if (unlikely(bq27xxx_battery_dead(di, flags)))
> +	if (unlikely(bq27xxx_battery_dead(di, di->cache.flags)))
>  		return POWER_SUPPLY_HEALTH_DEAD;
>  
>  	return POWER_SUPPLY_HEALTH_GOOD;
> @@ -1612,6 +1599,7 @@ void bq27xxx_battery_update(struct bq27xxx_device_info *di)
>  			cache.capacity = bq27xxx_battery_read_soc(di);
>  			if (di->regs[BQ27XXX_REG_AE] != INVALID_REG_ADDR)
>  				cache.energy = bq27xxx_battery_read_energy(di);
> +			di->cache.flags = cache.flags;
>  			cache.health = bq27xxx_battery_read_health(di);
>  		}
>  		if (di->regs[BQ27XXX_REG_CYCT] != INVALID_REG_ADDR)
>