[PATCH 1/1] UBUNTU: Input: i8042 - bypass AUX IRQ delivery test on laptops

[Stefan Bader]

Urgh, what a (hardware) mess. I guess IRQ12 widely (even for desktops) should
have always been used by the ps2 controller and so the assumption seems safe.
And we probably could assume that using the touchpad _is_ a critical part of the
system usage. So I would say ok with many sighs.

Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/534448
> 
> Touchpad detection fails for a bunch of laptops because of faulty
> AUX LOOP command implementation. This backport patch of commit
> upstream commit 1c7827ae70e7c8456e08f7bb9ef2238d27814cbe fixes this.
> 
> Quoting the original posting:
> 
> It seems that many laptops do not fully implement AUX LOOP command in
> their keyboard controllers, causing issues with touchpad detection.
> We know however that almost every laptop/portable uses a PS/2 pointing
> device and, even if user disables it in favor of an external mouse,
> the system will not use IRQ 12 for anything else. Therefore we may
> bypass AUX IRQ delivery test when running on a laptop and assume that
> it is routed properly.
> 
> Just to be safe we require the box to have good PNP data in order to
> bypass the test.
> 
> Signed-off-by: Dmitry Torokhov <dtor at mail.ru>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
Acked-by: Stefan Bader <stefan.bader at canonical.com>
> ---
>  drivers/input/serio/i8042-x86ia64io.h |   33 +++++++++++++++++++++++++++++++++
>  drivers/input/serio/i8042.c           |    4 +++-
>  2 files changed, 36 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h
> index ccbf23e..6e244a0 100644
> --- a/drivers/input/serio/i8042-x86ia64io.h
> +++ b/drivers/input/serio/i8042-x86ia64io.h
> @@ -457,6 +457,34 @@ static struct dmi_system_id __initdata i8042_dmi_nopnp_table[] = {
>  	},
>  	{ }
>  };
> +
> +static struct dmi_system_id __initdata i8042_dmi_laptop_table[] = {
> +	{
> +		.ident = "Portable",
> +		.matches = {
> +			DMI_MATCH(DMI_CHASSIS_TYPE, "8"), /* Portable */
> +		},
> +	},
> +	{
> +		.ident = "Laptop",
> +		.matches = {
> +			DMI_MATCH(DMI_CHASSIS_TYPE, "9"), /* Laptop */
> +		},
> +	},
> +	{
> +		.ident = "Notebook",
> +		.matches = {
> +			DMI_MATCH(DMI_CHASSIS_TYPE, "10"), /* Notebook */
> +		},
> +	},
> +	{
> +		.ident = "Sub-Notebook",
> +		.matches = {
> +			DMI_MATCH(DMI_CHASSIS_TYPE, "14"), /* Sub-Notebook */
> +		},
> +	},
> +	{ }
> +};
>  #endif
>  
>  /*
> @@ -735,6 +763,11 @@ static int __init i8042_pnp_init(void)
>  	i8042_kbd_irq = i8042_pnp_kbd_irq;
>  	i8042_aux_irq = i8042_pnp_aux_irq;
>  
> +#ifdef CONFIG_X86
> +	i8042_bypass_aux_irq_test = !pnp_data_busted &&
> +				    dmi_check_system(i8042_dmi_laptop_table);
> +#endif
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
> index 582245c..e8705fe 100644
> --- a/drivers/input/serio/i8042.c
> +++ b/drivers/input/serio/i8042.c
> @@ -83,6 +83,8 @@ module_param_named(debug, i8042_debug, bool, 0600);
>  MODULE_PARM_DESC(debug, "Turn i8042 debugging mode on and off");
>  #endif
>  
> +static bool i8042_bypass_aux_irq_test;
> +
>  #include "i8042.h"
>  
>  static DEFINE_SPINLOCK(i8042_lock);
> @@ -641,7 +643,7 @@ static int __devinit i8042_check_aux(void)
>   * used it for a PCI card or somethig else.
>   */
>  
> -	if (i8042_noloop || aux_loop_broken) {
> +	if (i8042_noloop || i8042_bypass_aux_irq_test || aux_loop_broken) {
>  /*
>   * Without LOOP command we can't test AUX IRQ delivery. Assume the port
>   * is working and hope we are right.