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Commit 0e9b4e53 authored by Bartlomiej Zolnierkiewicz's avatar Bartlomiej Zolnierkiewicz
Browse files

it821x: PIO mode setup fixes 



* limit max PIO mode to PIO4, this driver doesn't support PIO5 and attempt
  to setup PIO5 by it821x_tuneproc() could result in incorrect PIO timings
  + incorrect base clock being set for controller in the passthrough mode

* move code limiting max PIO according to the pair device capabilities from
  config_it821x_chipset_for_pio() to it821x_tuneproc() so the check is also
  applied for mode change requests coming through ->tuneproc and ->speedproc
  interfaces

* set device speed in it821x_tuneproc()

* in it821x_tune_chipset() call it821x_tuneproc() also if the controller is
  in the smart mode (so the check for pair device max PIO is done)

* rename it821x_tuneproc() to it821x_tune_pio(), then add it821x_tuneproc()
  wrapper which does the max PIO mode check;  it worked by the pure luck
  previously, pio[4] and pio_want[4] arrays were used with index == 255
  so random PIO timings and base clock were set for the controller in the
  passthrough mode, thankfully PIO timings and base clock were corrected
  later by config_it821x_chipset_for_pio() call (but it was not called for
  PIO-only devices during resume and for user requested PIO autotuning)

* remove config_it821x_chipset_for_pio() call from config_chipset_for_dma()
  as the driver sets ->autotune to 1 and ->tuneproc does the proper job now

* convert the last user of config_it821x_chipset_for_pio() to use
  it821x_tuneproc(drive, 255) and remove no longer needed function

While at it:

* fix few comments

* bump driver version

Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
parent 247b03f8

drivers/ide/pci/it821x.c

+58 −68
Original line number Diff line number Diff line 


/*

 * linux/drivers/ide/pci/it821x.c		Version 0.09	December 2004

 * linux/drivers/ide/pci/it821x.c		Version 0.10	Mar 10 2007

 *

 * Copyright (C) 2004		Red Hat <alan@redhat.com>

 * Copyright (C) 2007		Bartlomiej Zolnierkiewicz

 *

 *  May be copied or modified under the terms of the GNU General Public License

 *  Based in part on the ITE vendor provided SCSI driver.
@@ -104,6 +105,7 @@ static int it8212_noraid; 
/**

 *	it821x_program	-	program the PIO/MWDMA registers

 *	@drive: drive to tune

 *	@timing: timing info

 *

 *	Program the PIO/MWDMA timing for this channel according to the

 *	current clock.
@@ -127,6 +129,7 @@ static void it821x_program(ide_drive_t *drive, u16 timing) 
/**

 *	it821x_program_udma	-	program the UDMA registers

 *	@drive: drive to tune

 *	@timing: timing info

 *

 *	Program the UDMA timing for this drive according to the

 *	current clock.
@@ -153,10 +156,9 @@ static void it821x_program_udma(ide_drive_t *drive, u16 timing) 
	}

}





/**

 *	it821x_clock_strategy

 *	@hwif: hardware interface

 *	@drive: drive to set up

 *

 *	Select between the 50 and 66Mhz base clocks to get the best

 *	results for this interface.
@@ -182,7 +184,10 @@ static void it821x_clock_strategy(ide_drive_t *drive) 
		altclock = itdev->want[0][1];

	}



	/* Master doesn't care does the slave ? */

	/*

	 * if both clocks can be used for the mode with the higher priority

	 * use the clock needed by the mode with the lower priority

	 */

	if (clock == ATA_ANY)

		clock = altclock;
@@ -240,37 +245,56 @@ static u8 it821x_ratemask (ide_drive_t *drive) 
}



/**

 *	it821x_tuneproc	-	tune a drive

 *	it821x_tunepio	-	tune a drive

 *	@drive: drive to tune

 *	@mode_wanted: the target operating mode

 *

 *	Load the timing settings for this device mode into the

 *	controller. By the time we are called the mode has been

 *	modified as neccessary to handle the absence of seperate

 *	master/slave timers for MWDMA/PIO.

 *	@pio: the desired PIO mode

 *

 *	This code is only used in pass through mode.

 *	Try to tune the drive/host to the desired PIO mode taking into

 *	the consideration the maximum PIO mode supported by the other

 *	device on the cable.

 */



static void it821x_tuneproc (ide_drive_t *drive, byte mode_wanted)

static int it821x_tunepio(ide_drive_t *drive, u8 set_pio)

{

	ide_hwif_t *hwif	= drive->hwif;

	struct it821x_dev *itdev = ide_get_hwifdata(hwif);

	int unit = drive->select.b.unit;

	ide_drive_t *pair = &hwif->drives[1 - unit];



	/* Spec says 89 ref driver uses 88 */

	static u16 pio[]	= { 0xAA88, 0xA382, 0xA181, 0x3332, 0x3121 };

	static u8 pio_want[]    = { ATA_66, ATA_66, ATA_66, ATA_66, ATA_ANY };



	/*

	 * Compute the best PIO mode we can for a given device. We must

	 * pick a speed that does not cause problems with the other device

	 * on the cable.

	 */

	if (pair) {

		u8 pair_pio = ide_get_best_pio_mode(pair, 255, 4, NULL);

		/* trim PIO to the slowest of the master/slave */

		if (pair_pio < set_pio)

			set_pio = pair_pio;

	}



	if (itdev->smart)

		return;

		goto set_drive_speed;



	/* We prefer 66Mhz clock for PIO 0-3, don't care for PIO4 */

	itdev->want[unit][1] = pio_want[mode_wanted];

	itdev->want[unit][1] = pio_want[set_pio];

	itdev->want[unit][0] = 1;	/* PIO is lowest priority */

	itdev->pio[unit] = pio[mode_wanted];

	itdev->pio[unit] = pio[set_pio];

	it821x_clock_strategy(drive);

	it821x_program(drive, itdev->pio[unit]);



set_drive_speed:

	return ide_config_drive_speed(drive, XFER_PIO_0 + set_pio);

}



static void it821x_tuneproc(ide_drive_t *drive, u8 pio)

{

	pio = ide_get_best_pio_mode(drive, pio, 4, NULL);

	(void)it821x_tunepio(drive, pio);

}



/**
@@ -353,40 +377,6 @@ static void it821x_tune_udma (ide_drive_t *drive, byte mode_wanted) 


}



/**

 *	config_it821x_chipset_for_pio	-	set drive timings

 *	@drive: drive to tune

 *	@speed we want

 *

 *	Compute the best pio mode we can for a given device. We must

 *	pick a speed that does not cause problems with the other device

 *	on the cable.

 */



static void config_it821x_chipset_for_pio (ide_drive_t *drive, byte set_speed)

{

	u8 unit = drive->select.b.unit;

	ide_hwif_t *hwif = drive->hwif;

	ide_drive_t *pair = &hwif->drives[1-unit];

	u8 speed = 0, set_pio	= ide_get_best_pio_mode(drive, 255, 5, NULL);

	u8 pair_pio;



	/* We have to deal with this mess in pairs */

	if(pair != NULL) {

		pair_pio = ide_get_best_pio_mode(pair, 255, 5, NULL);

		/* Trim PIO to the slowest of the master/slave */

		if(pair_pio < set_pio)

			set_pio = pair_pio;

	}

	it821x_tuneproc(drive, set_pio);

	speed = XFER_PIO_0 + set_pio;

	/* XXX - We trim to the lowest of the pair so the other drive

	   will always be fine at this point until we do hotplug passthru */



	if (set_speed)

		(void) ide_config_drive_speed(drive, speed);

}



/**

 *	it821x_dma_read	-	DMA hook

 *	@drive: drive for DMA
@@ -450,15 +440,17 @@ static int it821x_tune_chipset (ide_drive_t *drive, byte xferspeed) 
	struct it821x_dev *itdev = ide_get_hwifdata(hwif);

	u8 speed		= ide_rate_filter(it821x_ratemask(drive), xferspeed);



	if(!itdev->smart) {

	switch (speed) {

	case XFER_PIO_4:

	case XFER_PIO_3:

	case XFER_PIO_2:

	case XFER_PIO_1:

	case XFER_PIO_0:

				it821x_tuneproc(drive, (speed - XFER_PIO_0));

				break;

		return it821x_tunepio(drive, speed - XFER_PIO_0);

	}



	if (itdev->smart == 0) {

		switch (speed) {

			/* MWDMA tuning is really hard because our MWDMA and PIO

			   timings are kept in the same place. We can switch in the

			   host dma on/off callbacks */
@@ -498,16 +490,14 @@ static int config_chipset_for_dma (ide_drive_t *drive) 
{

	u8 speed	= ide_dma_speed(drive, it821x_ratemask(drive));



	if (speed) {

		config_it821x_chipset_for_pio(drive, 0);

	if (speed == 0)

		return 0;



	it821x_tune_chipset(drive, speed);



	return ide_dma_enable(drive);

}



	return 0;

}



/**

 *	it821x_configure_drive_for_dma	-	set up for DMA transfers

 *	@drive: drive we are going to set up
@@ -523,7 +513,7 @@ static int it821x_config_drive_for_dma (ide_drive_t *drive) 
	if (ide_use_dma(drive) && config_chipset_for_dma(drive))

		return 0;



	config_it821x_chipset_for_pio(drive, 1);

	it821x_tuneproc(drive, 255);



	return -1;

}