[PATCH] 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: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
---
drivers/ide/pci/it821x.c | 126 +++++++++++++++++++++--------------------------
1 file changed, 58 insertions(+), 68 deletions(-)
Index: b/drivers/ide/pci/it821x.c
===================================================================
--- a/drivers/ide/pci/it821x.c
+++ b/drivers/ide/pci/it821x.c
@@ -1,8 +1,9 @@
/*
- * 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@xxxxxxxxxx>
+ * 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 *
/**
* 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_driv
}
}
-
/**
* 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.
@@ -182,8 +184,11 @@ static void it821x_clock_strategy(ide_dr
altclock = itdev->want[0][1];
}
- /* Master doesn't care does the slave ? */
- if(clock == ATA_ANY)
+ /*
+ * 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;
/* Nobody cares - keep the same clock */
@@ -224,37 +229,56 @@ static void it821x_clock_strategy(ide_dr
}
/**
- * 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 };
- if(itdev->smart)
- return;
+ /*
+ * 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)
+ 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);
}
/**
@@ -338,40 +362,6 @@ static void it821x_tune_udma (ide_drive_
}
/**
- * 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
*
@@ -434,15 +424,17 @@ static int it821x_tune_chipset (ide_driv
struct it821x_dev *itdev = ide_get_hwifdata(hwif);
u8 speed = ide_rate_filter(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;
+ switch (speed) {
+ case XFER_PIO_4:
+ case XFER_PIO_3:
+ case XFER_PIO_2:
+ case XFER_PIO_1:
+ case XFER_PIO_0:
+ 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 */
@@ -482,14 +474,12 @@ static int config_chipset_for_dma (ide_d
{
u8 speed = ide_max_dma_mode(drive);
- if (speed) {
- config_it821x_chipset_for_pio(drive, 0);
- it821x_tune_chipset(drive, speed);
+ if (speed == 0)
+ return 0;
- return ide_dma_enable(drive);
- }
+ it821x_tune_chipset(drive, speed);
- return 0;
+ return ide_dma_enable(drive);
}
/**
@@ -507,7 +497,7 @@ static int it821x_config_drive_for_dma (
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;
}
-
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