If U-Boot is not the first-stage bootloader the keyboard may already be set up. Make sure to flush any data before trying to reset it. This avoids a long timeout / hang.
Add some comments and a log category while we are here.
Signed-off-by: Simon Glass sjg@chromium.org ---
(no changes since v2)
Changes in v2: - Flush the buffer instead of skipping the reset
drivers/input/i8042.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/drivers/input/i8042.c b/drivers/input/i8042.c index 3563dc98838f..e6070ca01529 100644 --- a/drivers/input/i8042.c +++ b/drivers/input/i8042.c @@ -6,6 +6,8 @@
/* i8042.c - Intel 8042 keyboard driver routines */
+#define LOG_CATEGORY UCLASS_KEYBOARD + #include <common.h> #include <dm.h> #include <env.h> @@ -54,6 +56,14 @@ static unsigned char ext_key_map[] = { 0x00 /* map end */ };
+/** + * kbd_input_empty() - Wait until the keyboard is ready for a command + * + * Checks the IBF flag (input buffer full), waiting for it to indicate that + * any previous command has been processed. + * + * Return: true if ready, false if it timed out + */ static int kbd_input_empty(void) { int kbd_timeout = KBD_TIMEOUT * 1000; @@ -64,6 +74,12 @@ static int kbd_input_empty(void) return kbd_timeout != -1; }
+/** + * kbd_output_full() - Wait until the keyboard has data available + * + * Checks the OBF flag (output buffer full), waiting for it to indicate that + * a response to a previous command is available + */ static int kbd_output_full(void) { int kbd_timeout = KBD_TIMEOUT * 1000; @@ -127,6 +143,9 @@ static int kbd_reset(int quirk) { int config;
+ if (!kbd_input_empty()) + goto err; + /* controller self test */ if (kbd_cmd_read(CMD_SELF_TEST) != KBC_TEST_OK) goto err;