Commit 09c7ad79 authored by Alan Cox's avatar Alan Cox Committed by Jeff Garzik
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[PATCH] libata: Fix a drive detection problem 



The current code follows the spec but uses an overlong delay. This would
be great if the hardware did. Several vendors however forget the D7
pulldown. Fortunately 0xFF isnt a sane reset state so we can use it to
skip detection as is done in drivers/ide. (ie this is a tested solution
over a long time)

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 7c74ffd0

drivers/scsi/libata-core.c

+10 −0
Original line number Diff line number Diff line
@@ -2001,9 +2001,19 @@ static unsigned int ata_bus_softreset(struct ata_port *ap, 
	 * status is checked.  Because waiting for "a while" before

	 * checking status is fine, post SRST, we perform this magic

	 * delay here as well.

	 *

	 * Old drivers/ide uses the 2mS rule and then waits for ready

	 */

	msleep(150);



	

	/* Before we perform post reset processing we want to see if 

	   the bus shows 0xFF because the odd clown forgets the D7 pulldown

	   resistor */

	

	if (ata_check_status(ap) == 0xFF)

		return 1;	/* Positive is failure for some reason */



	ata_bus_post_reset(ap, devmask);



	return 0;