[PATCH] at_keyboard.c: add timeout to fix hang on hp elitebooks

[Riku Viitanen via Grub-devel]

This fixes GRUB on Coreboot on HP EliteBooks by implementing
a 200ms timeout. GRUB used to hang. See: https://ticket.coreboot.org/issues/141
---
 grub-core/term/at_keyboard.c | 11 ++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/grub-core/term/at_keyboard.c b/grub-core/term/at_keyboard.c
index 597111077..28d1d0a77 100644
--- a/grub-core/term/at_keyboard.c
+++ b/grub-core/term/at_keyboard.c
@@ -42,7 +42,16 @@ keyboard_controller_wait_until_ready (void)
 {
   /* 50 us would be enough but our current time resolution is 1ms.  */
   grub_millisleep (1);
-  while (! KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS)));
+
+  unsigned i = 200;
+  while (! KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS))) {
+grub_millisleep (1);
+
+/* Timeout */
+if (! i--) {
+  break;
+}
+  }
 }
 
 static grub_uint8_t
-- 
2.40.0

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Re: [PATCH] at_keyboard.c: add timeout to fix hang on hp elitebooks

[Vladimir 'phcoder' Serbinenko]

LGTM

On Sun, Apr 23, 2023 at 3:39 PM Riku Viitanen via Grub-devel
 wrote:
>
> This fixes GRUB on Coreboot on HP EliteBooks by implementing
> a 200ms timeout. GRUB used to hang. See: 
> https://ticket.coreboot.org/issues/141
> ---
>  grub-core/term/at_keyboard.c | 11 ++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/grub-core/term/at_keyboard.c b/grub-core/term/at_keyboard.c
> index 597111077..28d1d0a77 100644
> --- a/grub-core/term/at_keyboard.c
> +++ b/grub-core/term/at_keyboard.c
> @@ -42,7 +42,16 @@ keyboard_controller_wait_until_ready (void)
>  {
>/* 50 us would be enough but our current time resolution is 1ms.  */
>grub_millisleep (1);
> -  while (! KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS)));
> +
> +  unsigned i = 200;
> +  while (! KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS))) {
> +grub_millisleep (1);
> +
> +/* Timeout */
> +if (! i--) {
> +  break;
> +}
> +  }
>  }
>
>  static grub_uint8_t
> --
> 2.40.0
>
> ___
> Grub-devel mailing list
> Grub-devel@gnu.org
> https://lists.gnu.org/mailman/listinfo/grub-devel



-- 
Regards
Vladimir 'phcoder' Serbinenko

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