Re: [PATCH] mach-pxa/viper: Fix timeout usage for I2C

[Eric Miao <eric.y.miao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Sun, Apr 4, 2010 at 10:08 PM, Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> wrote:
> The timeout value is in jiffies, so it should be using HZ, not a plain
> number. Assume '100' means 100ms here and adapt accordingly.
>
> Signed-off-by: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Cc: Eric Miao <eric.y.miao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
> Cc: Marc Zyngier <maz-20xNzvSXLT6hUMvJH42dtQ@public.gmane.org>
> Cc: Paul Shen <paul.shen-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
> Cc: Mike Rapoport <mike-UTxiZqZC01RS1MOuV/RT9w@public.gmane.org>
> ---
>
> Janitorial fix, not tested due to no hardware.
>
>  arch/arm/mach-pxa/viper.c |    5 +++--
>  1 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-pxa/viper.c b/arch/arm/mach-pxa/viper.c
> index 1dd1334..c25921f 100644
> --- a/arch/arm/mach-pxa/viper.c
> +++ b/arch/arm/mach-pxa/viper.c
> @@ -33,6 +33,7 @@
>  #include <linux/pm.h>
>  #include <linux/sched.h>
>  #include <linux/gpio.h>
> +#include <linux/jiffies.h>
>  #include <linux/i2c-gpio.h>
>  #include <linux/serial_8250.h>
>  #include <linux/smc91x.h>
> @@ -453,7 +454,7 @@ static struct i2c_gpio_platform_data i2c_bus_data = {
>        .sda_pin = VIPER_RTC_I2C_SDA_GPIO,
>        .scl_pin = VIPER_RTC_I2C_SCL_GPIO,
>        .udelay  = 10,
> -       .timeout = 100,
> +       .timeout = HZ / 10,
>  };
>
>  static struct platform_device i2c_bus_device = {
> @@ -778,7 +779,7 @@ static void __init viper_tpm_init(void)
>                .sda_pin = VIPER_TPM_I2C_SDA_GPIO,
>                .scl_pin = VIPER_TPM_I2C_SCL_GPIO,
>                .udelay  = 10,
> -               .timeout = 100,
> +               .timeout = HZ / 10,
>        };
>        char *errstr;
>

One other better and cleaner approach to such inconsistency issue is
to have a timeout_ms field, and having i2c-gpio.c driver to convert this
to jiffies using msec_to_jiffies() at run-time.