| Message ID | 1321337892-12367-1-git-send-email-gabeblack@chromium.org |
|---|---|
| State | Accepted |
| Commit | 22e0f5a9ecab85f36a0fe69892d950c1ac212c91 |
| Delegated to: | Graeme Russ |
| Headers | show |
Hi Gabe, On 15/11/11 17:18, Gabe Black wrote: > If no controller is present, the i8402 driver should return immediately and > not attempt to operate on the missing hardware. > > In kbd_input_empty, the status register is checked every millisecond to see > whether the input buffer is empty, up to a timeout which is tracked by > decrimenting a counter each time the check is performed. The decrement is > performed with a postfix -- operator, and the value of the counter is > checked in place. That means that when the counter reaches zero and the > loop terminates, it will actually be decrimented one more time and become > -1. That value is returned as the return value of the function. That would > give the right answer if it wasn't for that extra decrement because a > timeout would indicate that the buffer never became empty. > > This change fixes both of those bugs. > > Signed-off-by: Gabe Black <gabeblack@chromium.org> > --- > Changes in v2: > - Change summary tag style. > - Rebase onto checkpatch cleaned file. > > drivers/input/i8042.c | 12 +++++++++++- > 1 files changed, 11 insertions(+), 1 deletions(-) Applied to u-boot-x86/master Thanks, Graeme
diff --git a/drivers/input/i8042.c b/drivers/input/i8042.c index 83b1bf4..c3bc536 100644 --- a/drivers/input/i8042.c +++ b/drivers/input/i8042.c @@ -313,6 +313,13 @@ static unsigned char ext_key_map[] = { 0x00 /* map end */ }; +/******************************************************************************/ + +static int kbd_controller_present(void) +{ + return in8(I8042_STATUS_REG) != 0xff; +} + /******************************************************************************* * * i8042_kbd_init - reset keyboard and init state flags @@ -322,6 +329,9 @@ int i8042_kbd_init(void) int keymap, try; char *penv; + if (!kbd_controller_present()) + return -1; + #ifdef CONFIG_USE_CPCIDVI penv = getenv("console"); if (penv != NULL) { @@ -603,7 +613,7 @@ static int kbd_input_empty(void) while ((in8(I8042_STATUS_REG) & 0x02) && kbdTimeout--) udelay(1000); - return kbdTimeout; + return kbdTimeout != -1; } /******************************************************************************/
If no controller is present, the i8402 driver should return immediately and not attempt to operate on the missing hardware. In kbd_input_empty, the status register is checked every millisecond to see whether the input buffer is empty, up to a timeout which is tracked by decrimenting a counter each time the check is performed. The decrement is performed with a postfix -- operator, and the value of the counter is checked in place. That means that when the counter reaches zero and the loop terminates, it will actually be decrimented one more time and become -1. That value is returned as the return value of the function. That would give the right answer if it wasn't for that extra decrement because a timeout would indicate that the buffer never became empty. This change fixes both of those bugs. Signed-off-by: Gabe Black <gabeblack@chromium.org> --- Changes in v2: - Change summary tag style. - Rebase onto checkpatch cleaned file. drivers/input/i8042.c | 12 +++++++++++- 1 files changed, 11 insertions(+), 1 deletions(-)