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Input: i8042 - fix AUX port detection with some chips

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The i8042 driver fails detection of the AUX port with some chips,
because they apparently do not change the I8042_CTR_AUXDIS bit
immediately. This is known to affect at least HP500/HP510 notebooks,
consequently the built-in touchpad will not work. The patch will simply
reread the value until it gets the expected value or a retry limit is
hit, without touching other workaround code in the same area.

Signed-off-by: Roland Scheidegger <sroland@tungstengraphics.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Roland Scheidegger 2007-05-08 01:31:40 -04:00 committed by Dmitry Torokhov
parent 334d0dd8b6
commit d2ada5597d
1 changed files with 29 additions and 6 deletions
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35
drivers/input/serio/i8042.c
View file

@ -526,6 +526,33 @@ static irqreturn_t __devinit i8042_aux_test_irq(int irq, void *dev_id)
return IRQ_HANDLED;
}
/*
* i8042_toggle_aux - enables or disables AUX port on i8042 via command and
* verifies success by readinng CTR. Used when testing for presence of AUX
* port.
*/
static int __devinit i8042_toggle_aux(int on)
{
unsigned char param;
int i;
if (i8042_command(&param,
on ? I8042_CMD_AUX_ENABLE : I8042_CMD_AUX_DISABLE))
return -1;
/* some chips need some time to set the I8042_CTR_AUXDIS bit */
for (i = 0; i < 100; i++) {
udelay(50);
if (i8042_command(&param, I8042_CMD_CTL_RCTR))
return -1;
if (!(param & I8042_CTR_AUXDIS) == on)
return 0;
}
return -1;
}
/*
* i8042_check_aux() applies as much paranoia as it can at detecting
@ -580,16 +607,12 @@ static int __devinit i8042_check_aux(void)
* Bit assignment test - filters out PS/2 i8042's in AT mode
*/
if (i8042_command(&param, I8042_CMD_AUX_DISABLE))
return -1;
if (i8042_command(&param, I8042_CMD_CTL_RCTR) || (~param & I8042_CTR_AUXDIS)) {
if (i8042_toggle_aux(0)) {
printk(KERN_WARNING "Failed to disable AUX port, but continuing anyway... Is this a SiS?\n");
printk(KERN_WARNING "If AUX port is really absent please use the 'i8042.noaux' option.\n");
}
if (i8042_command(&param, I8042_CMD_AUX_ENABLE))
return -1;
if (i8042_command(&param, I8042_CMD_CTL_RCTR) || (param & I8042_CTR_AUXDIS))
if (i8042_toggle_aux(1))
return -1;
/*