Commit d2ada559 authored by Roland Scheidegger's avatar Roland Scheidegger Committed by Dmitry Torokhov
Browse files

Input: i8042 - fix AUX port detection with some chips 



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: default avatarRoland Scheidegger <sroland@tungstengraphics.com>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 334d0dd8

drivers/input/serio/i8042.c

+29 −6
Original line number Diff line number Diff line
@@ -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;



/*

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