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libpayload: Remove unnecessary keyboard mode setting code 

keyboard_init attempts to read the existing mode register, set the
'XLATE' bit, and write it back. The implementation is buggy because the
keyboard may be active at the time we read the mode, and we can
misinterpret scancode data as the reply to our command. It leads to
problems where the KB gets disabled in firmware.

In fact, setting the 'XLATE' bit is completely unnecessary, even if we
desire QEMU keyboard support. We already set this bit when we initialize
the keyboard in pc_keyboard_init. Basically, this code does nothing
(or worse), so just remove it.

Change-Id: Iab23f03fa8bced74842c33a7d263de5f449bb983
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: http://review.coreboot.org/3883
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
This commit is contained in:
Shawn Nematbakhsh 2013-08-23 14:12:24 -07:00 committed by Stefan Reinauer
parent 5a7e127cd4
commit dd6c4ec1ed
1 changed files with 0 additions and 52 deletions
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52
payloads/libpayload/drivers/keyboard.c
View File

@ -31,11 +31,6 @@
#include <libpayload-config.h> #include <libpayload-config.h>
#include <libpayload.h> #include <libpayload.h>
#define I8042_CMD_READ_MODE 0x20
#define I8042_CMD_WRITE_MODE 0x60
#define I8042_MODE_XLATE 0x40
struct layout_maps { struct layout_maps {
const char *country; const char *country;
const unsigned short map[4][0x57]; const unsigned short map[4][0x57];
@ -261,40 +256,6 @@ int keyboard_getchar(void)
return ret; return ret;
} }
static int keyboard_wait_read(void)
{
int retries = 10000;
while(retries-- && !(inb(0x64) & 0x01))
udelay(50);
return (retries <= 0) ? -1 : 0;
}
static int keyboard_wait_write(void)
{
int retries = 10000;
while(retries-- && (inb(0x64) & 0x02))
udelay(50);
return (retries <= 0) ? -1 : 0;
}
static unsigned char keyboard_get_mode(void)
{
outb(I8042_CMD_READ_MODE, 0x64);
keyboard_wait_read();
return inb(0x60);
}
static void keyboard_set_mode(unsigned char mode)
{
outb(I8042_CMD_WRITE_MODE, 0x64);
keyboard_wait_write();
outb(mode, 0x60);
}
/** /**
* Set keyboard layout * Set keyboard layout
* @param country string describing the keyboard layout language. * @param country string describing the keyboard layout language.
@ -326,29 +287,16 @@ static struct console_input_driver cons = {
void keyboard_init(void) void keyboard_init(void)
{ {
u8 mode;
map = &keyboard_layouts[0]; map = &keyboard_layouts[0];
/* If 0x64 returns 0xff, then we have no keyboard /* If 0x64 returns 0xff, then we have no keyboard
* controller */ * controller */
if (inb(0x64) == 0xFF) if (inb(0x64) == 0xFF)
return; return;
/* Empty keyboard buffer */ /* Empty keyboard buffer */
while (keyboard_havechar()) keyboard_getchar(); while (keyboard_havechar()) keyboard_getchar();
/* Read the current mode */
mode = keyboard_get_mode();
/* Turn on scancode translate mode so that we can
use the scancode set 1 tables */
mode |= I8042_MODE_XLATE;
/* Write the new mode */
keyboard_set_mode(mode);
console_add_input_driver(&cons); console_add_input_driver(&cons);
} }