Commit f343e578 authored by Ondrej Zary's avatar Ondrej Zary Committed by Damien Le Moal
Browse files

ata: pata_parport: add custom version of wait_after_reset 



Some parallel adapters (e.g. EXP Computer MC-1285B EPP Cable) return
bogus values when there's no master device present. This can cause
reset to fail, preventing the lone slave device (such as EXP Computer
CD-865) from working.

Add custom version of wait_after_reset that ignores master failure when
a slave device is present. The custom version is also needed because
the generic ata_sff_wait_after_reset uses direct port I/O for slave
device detection.

Signed-off-by: default avatarOndrej Zary <linux@zary.sk>
Reviewed-by: default avatarSergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: default avatarDamien Le Moal <dlemoal@kernel.org>
parent d2302427

drivers/ata/pata_parport/pata_parport.c

+67 −1
Original line number Diff line number Diff line
@@ -80,6 +80,72 @@ static bool pata_parport_devchk(struct ata_port *ap, unsigned int device) 
	return (nsect == 0x55) && (lbal == 0xaa);

}



static int pata_parport_wait_after_reset(struct ata_link *link,

					 unsigned int devmask,

					 unsigned long deadline)

{

	struct ata_port *ap = link->ap;

	struct pi_adapter *pi = ap->host->private_data;

	unsigned int dev0 = devmask & (1 << 0);

	unsigned int dev1 = devmask & (1 << 1);

	int rc, ret = 0;



	ata_msleep(ap, ATA_WAIT_AFTER_RESET);



	/* always check readiness of the master device */

	rc = ata_sff_wait_ready(link, deadline);

	if (rc) {

		/*

		 * some adapters return bogus values if master device is not

		 * present, so don't abort now if a slave device is present

		 */

		if (!dev1)

			return rc;

		ret = -ENODEV;

	}



	/*

	 * if device 1 was found in ata_devchk, wait for register

	 * access briefly, then wait for BSY to clear.

	 */

	if (dev1) {

		int i;



		pata_parport_dev_select(ap, 1);



		/*

		 * Wait for register access.  Some ATAPI devices fail

		 * to set nsect/lbal after reset, so don't waste too

		 * much time on it.  We're gonna wait for !BSY anyway.

		 */

		for (i = 0; i < 2; i++) {

			u8 nsect, lbal;



			nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);

			lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL);

			if (nsect == 1 && lbal == 1)

				break;

			/* give drive a breather */

			ata_msleep(ap, 50);

		}



		rc = ata_sff_wait_ready(link, deadline);

		if (rc) {

			if (rc != -ENODEV)

				return rc;

			ret = rc;

		}

	}



	pata_parport_dev_select(ap, 0);

	if (dev1)

		pata_parport_dev_select(ap, 1);

	if (dev0)

		pata_parport_dev_select(ap, 0);



	return ret;

}



static int pata_parport_bus_softreset(struct ata_port *ap, unsigned int devmask,

				      unsigned long deadline)

{
@@ -94,7 +160,7 @@ static int pata_parport_bus_softreset(struct ata_port *ap, unsigned int devmask, 
	ap->last_ctl = ap->ctl;



	/* wait the port to become ready */

	return ata_sff_wait_after_reset(&ap->link, devmask, deadline);

	return pata_parport_wait_after_reset(&ap->link, devmask, deadline);

}



static int pata_parport_softreset(struct ata_link *link, unsigned int *classes,