Commit 81d368e0 authored by Sergei Shtylyov's avatar Sergei Shtylyov Committed by Bartlomiej Zolnierkiewicz
Browse files

ide: ide_get_best_pio_mode() returns incorrect IORDY setting (take 2) 



The function ide_get_best_pio_mode() fails to return the correct IORDY setting
for the explicitly specified modes -- fix this along with the heading comment,
and also remove the long commented out code.

Also, while at it, correct the misliading comment about the PIO cycle time in
<linux/ide.h> -- it actually consists of only the active and recovery periods,
with only some chips also including the address setup time into equation...

[ bart: sl82c105 seems to be currently the only driver affected by this fix ]

Signed-off-by: default avatarSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
parent 07af4276

drivers/ide/ide-lib.c

+6 −12
Original line number Diff line number Diff line
@@ -345,16 +345,16 @@ static int ide_scan_pio_blacklist (char *model) 


/**

 *	ide_get_best_pio_mode	-	get PIO mode from drive

 *	@driver: drive to consider

 *	@drive: drive to consider

 *	@mode_wanted: preferred mode

 *	@max_mode: highest allowed

 *	@d: pio data

 *	@max_mode: highest allowed mode

 *	@d: PIO data

 *

 *	This routine returns the recommended PIO settings for a given drive,

 *	based on the drive->id information and the ide_pio_blacklist[].

 *	This is used by most chipset support modules when "auto-tuning".

 *

 *	Drive PIO mode auto selection

 *	Drive PIO mode is auto-selected if 255 is passed as mode_wanted.

 *	This is used by most chipset support modules when "auto-tuning".

 */



u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode, ide_pio_data_t *d)
@@ -367,6 +367,7 @@ u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode, ide_p 


	if (mode_wanted != 255) {

		pio_mode = mode_wanted;

		use_iordy = (pio_mode > 2);

	} else if (!drive->id) {

		pio_mode = 0;

	} else if ((pio_mode = ide_scan_pio_blacklist(id->model)) != -1) {
@@ -396,19 +397,12 @@ u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode, ide_p 
			}

		}



#if 0

		if (drive->id->major_rev_num & 0x0004) printk("ATA-2 ");

#endif



		/*

		 * Conservative "downgrade" for all pre-ATA2 drives

		 */

		if (pio_mode && pio_mode < 4) {

			pio_mode--;

			overridden = 1;

#if 0

			use_iordy = (pio_mode > 2);

#endif

			if (cycle_time && cycle_time < ide_pio_timings[pio_mode].cycle_time)

				cycle_time = 0; /* use standard timing */

		}

include/linux/ide.h

+2 −1
Original line number Diff line number Diff line
@@ -1359,7 +1359,8 @@ u8 ide_dump_status(ide_drive_t *, const char *, u8); 
typedef struct ide_pio_timings_s {

	int	setup_time;	/* Address setup (ns) minimum */

	int	active_time;	/* Active pulse (ns) minimum */

	int	cycle_time;	/* Cycle time (ns) minimum = (setup + active + recovery) */

	int	cycle_time;	/* Cycle time (ns) minimum = */

				/* active + recovery (+ setup for some chips) */

} ide_pio_timings_t;



typedef struct ide_pio_data_s {

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