Re: [PATCH 1/1] Elantech touchpad detection fix for laptops

[Dmitry Torokhov]

Hi Srihari,

On Wed, Dec 24, 2014 at 09:52:40AM +1100, Srihari Vijayaraghavan wrote:
> [After trying a number of times to unsuccessfully send this to linux-input,
> am sending this to linux-kernel as the last resort.]

You are sending HTML mails and vger lists (pretty much all Linux
kernel-related lists) drop such mails on the floor. Please resend your
patch as plain/text only and it will be accepted by vger.

Thanks.

> 
> Hello Linux-Kernel Folks,
> 
> Months ago, I raised kernel bugzilla 81331 (
> https://bugzilla.kernel.org/show_bug.cgi?id=81331) for Linux not detecting
> my Elantech touchpad from a cold boot. As can be seen in that bug report,
> besides myself, it's indeed affecting a number of other users.
> 
> Since then, based on the original patch fix given by Mateusz Jonczyk, I've
> extended it to be this (which not only fixes my problem, but one another
> user has confirmed it to work for him; and am confident that every one of
> the affected user would be benefited too) & would appreciate your review
> (and inputs thereof) & if you're happy with it, then request you to kindly
> merge it upstream on mainline & stable.
> 
> On behalf of all affected users, much appreciate your help in this matter.
> Because I'm not subscribed to lkml, please address me directly in your
> response(s). Thank you.
> 
> PS: If gmail somehow spoils this patch, then please refer to the above
> kernel bugzilla URL, where the same patch is available as the most recent
> file attachment.
> 
> diff --git a/Documentation/kernel-
> parameters.txt b/Documentation/kernel-parameters.txt
> index 479f332..5ae99f3 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -1270,6 +1270,7 @@ bytes respectively. Such letter suffixes can also be
> entirely omitted.
>         i8042.notimeout [HW] Ignore timeout condition signalled by
> controller
>         i8042.reset     [HW] Reset the controller during init and cleanup
>         i8042.unlock    [HW] Unlock (ignore) the keylock
> +       i8042.kbdreset  [HW] Reset keyboard to detect Elantech touchpad
> 
>         i810=           [HW,DRM]
> 
> diff --git a/drivers/input/serio/i8042-x86ia64io.h
> b/drivers/input/serio/i8042-x86ia64io.h
> index faeeb13..40e85ed 100644
> --- a/drivers/input/serio/i8042-x86ia64io.h
> +++ b/drivers/input/serio/i8042-x86ia64io.h
> @@ -735,6 +735,29 @@ static const struct dmi_system_id __initconst
> i8042_dmi_dritek_table[] = {
>         { }
>  };
> 
> +/*
> + * Just as per kernel bugzilla #81331, some Elantech touchpad based laptops
> + * -- e.g., Gigabyte P35 v2, Gigabyte X3 Plus -- need keyboard reset while
> + * probing for the touchpad to get detected, initialised & finally work.
> + */
> +static const struct dmi_system_id __initconst
> i8042_dmi_elantech_kbdreset_table[] = {
> +        {
> +                /* Gigabyte P35 v2 */
> +                .matches = {
> +                        DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
> +                        DMI_MATCH(DMI_PRODUCT_NAME, "P35V2"),
> +                },
> +        },
> +       {
> +               /* Aorus branded Gigabyte X3 Plus */
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "X3"),
> +               },
> +       },
> +       { }
> +};
> +
>  #endif /* CONFIG_X86 */
> 
>  #ifdef CONFIG_PNP
> @@ -1030,6 +1053,9 @@ static int __init i8042_platform_init(void)
>         if (dmi_check_system(i8042_dmi_dritek_table))
>                 i8042_dritek = true;
> 
> +       if (dmi_check_system(i8042_dmi_elantech_kbdreset_table))
> +               i8042_kbdreset = true;
> +
>         /*
>          * A20 was already enabled during early kernel init. But some buggy
>          * BIOSes (in MSI Laptops) require A20 to be enabled using 8042 to
> diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
> index f5a98af..7cf42df 100644
> --- a/drivers/input/serio/i8042.c
> +++ b/drivers/input/serio/i8042.c
> @@ -67,6 +67,10 @@ static bool i8042_notimeout;
>  module_param_named(notimeout, i8042_notimeout, bool, 0);
>  MODULE_PARM_DESC(notimeout, "Ignore timeouts signalled by i8042");
> 
> +static bool i8042_kbdreset;
> +module_param_named(kbdreset, i8042_kbdreset, bool, 0);
> +MODULE_PARM_DESC(kbdreset, "Reset keyboard to detect Elantech touchpad on
> some laptops");
> +
>  #ifdef CONFIG_X86
>  static bool i8042_dritek;
>  module_param_named(dritek, i8042_dritek, bool, 0);
> @@ -790,6 +794,14 @@ static int __init i8042_check_aux(void)
>                 return -1;
> 
>  /*
> + * Reset keyboard to detect touchpad on some laptops having Elantech
> touchpad
> + */
> +       if (i8042_kbdreset) {
> +               pr_warn("Resetting keyboard to detect Elantech touchpad on
> some laptops\n");
> +               i8042_kbd_write(NULL, (unsigned char) 0xff);
> +       }
> +
> +/*
>   * Test AUX IRQ delivery to make sure BIOS did not grab the IRQ and
>   * used it for a PCI card or somethig else.
>   */


-- 
Dmitry
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