Re: [PATCH 10/15] ide: add ide_set_dma() helper

From: Sergei Shtylyov
Date: Sat Jan 20 2007 - 15:22:33 EST


Hello again. :-)

Bartlomiej Zolnierkiewicz wrote:
[PATCH] ide: add ide_set_dma() helper

* add ide_set_dma() helper and make ide_hwif_t.ide_dma_check return
-1 when DMA needs to be disabled (== need to call ->ide_dma_off_quietly)
0 when DMA needs to be enabled (== need to call ->ide_dma_on)
1 when DMA setting shouldn't be changed
* fix IDE code to use ide_set_dma() instead if using ->ide_dma_check directly

Here are a few comments related to the code being patched:

Index: b/drivers/ide/pci/alim15x3.c
===================================================================
--- a/drivers/ide/pci/alim15x3.c
+++ b/drivers/ide/pci/alim15x3.c
@@ -507,17 +507,15 @@ static int config_chipset_for_dma (ide_d
*
* Configure a drive for DMA operation. If DMA is not possible we
* drop the drive into PIO mode instead.
- *
- * FIXME: exactly what are we trying to return here
*/
- +
static int ali15x3_config_drive_for_dma(ide_drive_t *drive)
{
ide_hwif_t *hwif = HWIF(drive);
struct hd_driveid *id = drive->id;
if ((m5229_revision<=0x20) && (drive->media!=ide_disk))
- return hwif->ide_dma_off_quietly(drive);
+ goto no_dma_set;

Isn't it better to just return -1?

@@ -552,9 +550,10 @@ try_dma_modes:
ata_pio:
hwif->tuneproc(drive, 255);
no_dma_set:
- return hwif->ide_dma_off_quietly(drive);
+ return -1;
}
- return hwif->ide_dma_on(drive);
+
+ return 0;
}

Ugh, this code looks like it's asking to be converted into calling ide_use_dma(). instead all of that...

Index: b/drivers/ide/pci/cs5520.c
===================================================================
--- a/drivers/ide/pci/cs5520.c
+++ b/drivers/ide/pci/cs5520.c
@@ -132,12 +132,11 @@ static void cs5520_tune_drive(ide_drive_
static int cs5520_config_drive_xfer_rate(ide_drive_t *drive)
{
- ide_hwif_t *hwif = HWIF(drive);
-
/* Tune the drive for PIO modes up to PIO 4 */
cs5520_tune_drive(drive, 4);

Ugh. Why not ask drive? :-/

/* Then tell the core to use DMA operations */
- return hwif->ide_dma_on(drive);
+ return 0;

That must be the famous VDMA thing... :-)
I wonder if it *actually* works on HPT36x/37x which seem to have support for it...

Index: b/drivers/ide/pci/jmicron.c
===================================================================
--- a/drivers/ide/pci/jmicron.c
+++ b/drivers/ide/pci/jmicron.c
@@ -164,14 +164,12 @@ static int config_chipset_for_dma (ide_d
static int jmicron_config_drive_for_dma (ide_drive_t *drive)
{
- ide_hwif_t *hwif = drive->hwif;
+ if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+ return 0;
- if (ide_use_dma(drive)) {
- if (config_chipset_for_dma(drive))
- return hwif->ide_dma_on(drive);
- }
config_jmicron_chipset_for_pio(drive, 1);

The 2nd argument of that funtion is useless -- it basically does nothing if 0 is passed. Another case of mindless copy-paste. :-)

Index: b/drivers/ide/pci/pdc202xx_old.c
===================================================================
--- a/drivers/ide/pci/pdc202xx_old.c
+++ b/drivers/ide/pci/pdc202xx_old.c
@@ -332,17 +332,15 @@ chipset_is_set:
static int pdc202xx_config_drive_xfer_rate (ide_drive_t *drive)
{
- ide_hwif_t *hwif = HWIF(drive);
-
drive->init_speed = 0;
if (ide_use_dma(drive) && config_chipset_for_dma(drive))
- return hwif->ide_dma_on(drive);
+ return 0;
if (ide_use_fast_pio(drive))
- hwif->tuneproc(drive, 5);
+ config_chipset_for_pio(drive, 5);

That part is obsoleted by my recent fix...

Index: b/drivers/ide/pci/piix.c
===================================================================
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -386,20 +386,18 @@ static int piix_config_drive_for_dma (id
static int piix_config_drive_xfer_rate (ide_drive_t *drive)
{
- ide_hwif_t *hwif = HWIF(drive);
-
drive->init_speed = 0;
if (ide_use_dma(drive) && piix_config_drive_for_dma(drive))
- return hwif->ide_dma_on(drive);
+ return 0;
if (ide_use_fast_pio(drive)) {
/* Find best PIO mode. */
- (void) hwif->speedproc(drive, XFER_PIO_0 +
- ide_get_best_pio_mode(drive, 255, 4, NULL));
+ u8 pio = ide_get_best_pio_mode(drive, 255, 4, NULL);
+ (void)piix_tune_chipset(drive, XFER_PIO_0 + pio);
}

Will try to fix the tuneproc() nuisance RSN. :-)

Index: b/drivers/ide/pci/serverworks.c
===================================================================
--- a/drivers/ide/pci/serverworks.c
+++ b/drivers/ide/pci/serverworks.c
@@ -315,17 +315,15 @@ static int config_chipset_for_dma (ide_d
static int svwks_config_drive_xfer_rate (ide_drive_t *drive)
{
- ide_hwif_t *hwif = HWIF(drive);
-
drive->init_speed = 0;
if (ide_use_dma(drive) && config_chipset_for_dma(drive))
- return hwif->ide_dma_on(drive);
+ return 0;
if (ide_use_fast_pio(drive))
config_chipset_for_pio(drive);

I have no idea why that function is so huge in this driver, i.e. why all this code is not in svwks_tune_chipset()...

- return hwif->ide_dma_off_quietly(drive);
+ return -1;
}
static unsigned int __devinit init_chipset_svwks (struct pci_dev *dev, const char *name)
Index: b/drivers/ide/pci/sl82c105.c
===================================================================
--- a/drivers/ide/pci/sl82c105.c
+++ b/drivers/ide/pci/sl82c105.c
@@ -161,14 +161,14 @@ static int sl82c105_check_drive (ide_dri
if (id->field_valid & 2) {
if ((id->dma_mword & hwif->mwdma_mask) ||
(id->dma_1word & hwif->swdma_mask))

Ugh. This driver claims the full MW/SW DMA support while actually only supports MWDMA2.

- return hwif->ide_dma_on(drive);
+ return 0;
}
if (__ide_dma_good_drive(drive))
- return hwif->ide_dma_on(drive);
+ return 0;
} while (0);

This also asks to be converted into ide_use_dma() call. The patch is cooking...

- return hwif->ide_dma_off_quietly(drive);
+ return -1;
}
/*
Index: b/drivers/ide/pci/slc90e66.c
===================================================================
--- a/drivers/ide/pci/slc90e66.c
+++ b/drivers/ide/pci/slc90e66.c
@@ -179,19 +179,17 @@ static int slc90e66_config_drive_for_dma
static int slc90e66_config_drive_xfer_rate (ide_drive_t *drive)
{
- ide_hwif_t *hwif = HWIF(drive);
-
drive->init_speed = 0;
if (ide_use_dma(drive) && slc90e66_config_drive_for_dma(drive))
- return hwif->ide_dma_on(drive);
+ return 0;
if (ide_use_fast_pio(drive)) {
- (void) hwif->speedproc(drive, XFER_PIO_0 +
- ide_get_best_pio_mode(drive, 255, 4, NULL));
+ u8 pio = ide_get_best_pio_mode(drive, 255, 4, NULL);
+ (void)slc90e66_tune_chipset(drive, XFER_PIO_0 + pio);
}

The same promise about tuneproc() in this driver... :-)

MBR, Sergei
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/