From: Riku Viitanen <riku.viitanen@protonmail.com>
Date: Sun, 23 Apr 2023 09:59:34 +0000 (+0000)
Subject: term/at_keyboard: Add timeout to fix hang on HP EliteBooks
X-Git-Tag: grub-2.12-rc1~92
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=830456a6e3b6ac92d10f9261177722a308652a1a;p=thirdparty%2Fgrub.git

term/at_keyboard: Add timeout to fix hang on HP EliteBooks

This fixes the GRUB on Coreboot on HP EliteBooks by implementing
a 200 ms timeout. The GRUB used to hang.

Fixes: https://ticket.coreboot.org/issues/141

Signed-off-by: Riku Viitanen <riku.viitanen@protonmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---

diff --git a/grub-core/term/at_keyboard.c b/grub-core/term/at_keyboard.c
index 597111077..f8a129eb7 100644
--- a/grub-core/term/at_keyboard.c
+++ b/grub-core/term/at_keyboard.c
@@ -40,9 +40,19 @@ grub_keyboard_controller_init (void);
 static void
 keyboard_controller_wait_until_ready (void)
 {
+  unsigned int i = 200;
+
   /* 50 us would be enough but our current time resolution is 1ms.  */
   grub_millisleep (1);
-  while (! KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS)));
+
+  while (!KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS)))
+    {
+      grub_millisleep (1);
+
+      /* Timeout. */
+      if (!i--)
+	break;
+    }
 }
 
 static grub_uint8_t