From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Renaud=20M=C3=A9trich?= <rmetrich@redhat.com>
Date: Thu, 3 Dec 2020 09:13:24 +0100
Subject: [PATCH] at_keyboard: use set 1 when keyboard is in Translate mode
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When keyboard controller acts in Translate mode (0x40 mask), then use
set 1 since translation is done.
Otherwise use the mode queried from the controller (usually set 2).

Added "atkeyb" debugging messages in at_keyboard module as well.

Resolves: rhbz#1897587

Tested on:
- Asus N53SN (set 1 used)
- Dell Precision (set 1 used)
- HP Elitebook (set 2 used)
- HP G5430 (set 1 used, keyboard in XT mode!)
- Lenovo P71 & Lenovo T460s (set 2 used)
- QEMU/KVM (set 1 used)

Signed-off-by: Renaud M├ętrich <rmetrich@redhat.com>
---
 grub-core/term/at_keyboard.c | 29 ++++++++++++++++++++++++-----
 include/grub/at_keyboard.h   |  4 ++++
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/grub-core/term/at_keyboard.c b/grub-core/term/at_keyboard.c
index 597111077b..2601438260 100644
--- a/grub-core/term/at_keyboard.c
+++ b/grub-core/term/at_keyboard.c
@@ -135,20 +135,28 @@ query_mode (void)
   int e;
 
   e = write_mode (0);
-  if (!e)
+  if (!e) {
+    grub_dprintf("atkeyb", "query_mode: write_mode(0) failed\n");
     return 0;
+  }
 
   do {
     keyboard_controller_wait_until_ready ();
     ret = grub_inb (KEYBOARD_REG_DATA);
   } while (ret == GRUB_AT_ACK);
   /* QEMU translates the set even in no-translate mode.  */
-  if (ret == 0x43 || ret == 1)
+  if (ret == 0x43 || ret == 1) {
+    grub_dprintf("atkeyb", "query_mode: returning 1 (ret=0x%x)\n", ret);
     return 1;
-  if (ret == 0x41 || ret == 2)
+  }
+  if (ret == 0x41 || ret == 2) {
+    grub_dprintf("atkeyb", "query_mode: returning 2 (ret=0x%x)\n", ret);
     return 2;
-  if (ret == 0x3f || ret == 3)
+  }
+  if (ret == 0x3f || ret == 3) {
+    grub_dprintf("atkeyb", "query_mode: returning 3 (ret=0x%x)\n", ret);
     return 3;
+  }
   return 0;
 }
 
@@ -165,7 +173,13 @@ set_scancodes (void)
     }
 
 #if !USE_SCANCODE_SET
-  ps2_state.current_set = 1;
+  if ((grub_keyboard_controller_orig & KEYBOARD_AT_TRANSLATE) == KEYBOARD_AT_TRANSLATE) {
+    grub_dprintf ("atkeyb", "queried set is %d but keyboard in Translate mode, so actually in set 1\n", grub_keyboard_orig_set);
+    ps2_state.current_set = 1;
+  } else {
+    grub_dprintf ("atkeyb", "using queried set %d\n", grub_keyboard_orig_set);
+    ps2_state.current_set = grub_keyboard_orig_set;
+  }
   return;
 #else
 
@@ -266,6 +280,7 @@ grub_keyboard_controller_init (void)
   grub_keyboard_orig_set = 2;
 #else
   grub_keyboard_controller_orig = grub_keyboard_controller_read ();
+  grub_dprintf ("atkeyb", "grub_keyboard_controller_orig = 0x%x\n", grub_keyboard_controller_orig);
   grub_keyboard_orig_set = query_mode ();
 #endif
   set_scancodes ();
@@ -275,11 +290,15 @@ grub_keyboard_controller_init (void)
 static grub_err_t
 grub_keyboard_controller_fini (struct grub_term_input *term __attribute__ ((unused)))
 {
+/* In !USE_SCANCODE_SET mode, we didn't change anything, so nothing to restore */
+#if USE_SCANCODE_SET
   if (ps2_state.current_set == 0)
     return GRUB_ERR_NONE;
+  grub_dprintf ("atkeyb", "restoring set %d, controller 0x%x\n", grub_keyboard_orig_set, grub_keyboard_controller_orig);
   if (grub_keyboard_orig_set)
     write_mode (grub_keyboard_orig_set);
   grub_keyboard_controller_write (grub_keyboard_controller_orig);
+#endif
   return GRUB_ERR_NONE;
 }
 
diff --git a/include/grub/at_keyboard.h b/include/grub/at_keyboard.h
index bcb4d9ba78..9414dc1b99 100644
--- a/include/grub/at_keyboard.h
+++ b/include/grub/at_keyboard.h
@@ -19,6 +19,10 @@
 #ifndef GRUB_AT_KEYBOARD_HEADER
 #define GRUB_AT_KEYBOARD_HEADER	1
 
+/*
+ * Refer to https://wiki.osdev.org/%228042%22_PS/2_Controller for details.
+ */
+
 /* Used for sending commands to the controller.  */
 #define KEYBOARD_COMMAND_ISREADY(x)	!((x) & 0x02)
 #define KEYBOARD_COMMAND_READ		0x20