Re: [PATCH] Longhaul: Disable driver by default

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday, November 27, 2012 10:13:55 PM Rafal Bilski wrote:
> This is only solution I can think of. User decides if he wants this
> driver on his machine. I don't have enough knowledge and time to find
> the reason why same code works on some machines and doesn't on others
> which use same, or very similar,  chipset and processor.

I always have problems with patches like this one, because they are pretty much
guaranteed to make someone complain.

Is there any way to blacklist the affected machine you have?

Rafael


> Signed-off-by: Rafal Bilski <rafalbilski@interia.pl>
> 
> ---
>  drivers/cpufreq/longhaul.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
> index 53ddbc7..0bf5bd1 100644
> --- a/drivers/cpufreq/longhaul.c
> +++ b/drivers/cpufreq/longhaul.c
> @@ -77,7 +77,7 @@ static unsigned int longhaul_index;
>  static int scale_voltage;
>  static int disable_acpi_c3;
>  static int revid_errata;
> -
> +static int enable;
>  
>  /* Clock ratios multiplied by 10 */
>  static int mults[32];
> @@ -965,6 +965,10 @@ static int __init longhaul_init(void)
>  	if (!x86_match_cpu(longhaul_id))
>  		return -ENODEV;
>  
> +	if (!enable) {
> +		printk(KERN_ERR PFX "Option \"enable\" not set. Aborting.\n");
> +		return -ENODEV;
> +	}
>  #ifdef CONFIG_SMP
>  	if (num_online_cpus() > 1) {
>  		printk(KERN_ERR PFX "More than 1 CPU detected, "
> @@ -1021,6 +1025,10 @@ MODULE_PARM_DESC(scale_voltage, "Scale voltage of processor");
>   * such. */
>  module_param(revid_errata, int, 0644);
>  MODULE_PARM_DESC(revid_errata, "Ignore CPU Revision ID");
> +/* By default driver is disabled to prevent incompatible
> + * system freeze. */
> +module_param(enable, int, 0644);
> +MODULE_PARM_DESC(enable, "Enable driver");
>  
>  MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
>  MODULE_DESCRIPTION("Longhaul driver for VIA Cyrix processors.");
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.