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Commit b740d884 authored by Bartlomiej Zolnierkiewicz's avatar Bartlomiej Zolnierkiewicz
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serverworks: always tune CSB6 



Switch the driver to always program DMA/PIO timings and set device transfer
mode instead of trusting BIOS on CSB6 controllers (libata pata_serverworks.c
driver is also doing things this way and there were no problems reported so
far).  While doing conversion I noticed that the old code had many issues:

* the code was assuming that hwif->dma_status is always valid
  (which obviously isn't true if hwif->dma_base == NULL)

* value of "(ultra_timing >> (4*unit)) & ~(0xF0)" expression wasn't checked
  to fit into udma_modes[5]

* code validating DMA timings didn't validate corresponding PIO timings

* extra CSB5 PIO register wasn't validated et all

* hwif->ide_dma_off_quietly() is always called before ide_set_dma() (which in
  turn calls hwif->speedproc() method - svwks_tune_chipset() in this case)
  so the code depending on DMA capable bit of DMA status to be set was never
  executed (=> the code was never validating DMA timings despite actually
  enabling DMA if the PIO timings were OK!)

* on resume driver dependend entirely on BIOS to restore timings and set
  transfer mode on the device

While at it:

There is no need to read PIO/MWDMA timings now so don't do it.

Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: default avatarAlan Cox <alan@lxorguk.ukuu.org.uk>
parent 71d441dd

drivers/ide/pci/serverworks.c

+2 −75
Original line number Original line Diff line number Diff line 
/*

/*

 * linux/drivers/ide/pci/serverworks.c		Version 0.11	Jun 2 2007

 * linux/drivers/ide/pci/serverworks.c		Version 0.20	Jun 3 2007

 *

 *

 * Copyright (C) 1998-2000 Michel Aubry

 * Copyright (C) 1998-2000 Michel Aubry

 * Copyright (C) 1998-2000 Andrzej Krzysztofowicz

 * Copyright (C) 1998-2000 Andrzej Krzysztofowicz
@@ -152,83 +152,10 @@ static int svwks_tune_chipset (ide_drive_t *drive, u8 xferspeed) 
		drive->media == ide_disk && speed >= XFER_UDMA_0)

		drive->media == ide_disk && speed >= XFER_UDMA_0)

			BUG();

			BUG();





	pci_read_config_byte(dev, drive_pci[drive->dn], &pio_timing);

	pci_read_config_byte(dev, drive_pci2[drive->dn], &dma_timing);

	pci_read_config_byte(dev, (0x56|hwif->channel), &ultra_timing);

	pci_read_config_byte(dev, (0x56|hwif->channel), &ultra_timing);

	pci_read_config_word(dev, 0x4A, &csb5_pio);

	pci_read_config_word(dev, 0x4A, &csb5_pio);

	pci_read_config_byte(dev, 0x54, &ultra_enable);

	pci_read_config_byte(dev, 0x54, &ultra_enable);





	/* If we are in RAID mode (eg AMI MegaIDE) then we can't it

	   turns out trust the firmware configuration */



	if ((dev->class >> 8) != PCI_CLASS_STORAGE_IDE)

		goto oem_setup_failed;



	/* Per Specified Design by OEM, and ASIC Architect */

	if ((dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE) ||

	    (dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2)) {

		if (!drive->init_speed) {

			u8 dma_stat = inb(hwif->dma_status);



			if (((ultra_enable << (7-drive->dn) & 0x80) == 0x80) &&

			    ((dma_stat & (1<<(5+unit))) == (1<<(5+unit)))) {

				drive->current_speed = drive->init_speed = XFER_UDMA_0 + udma_modes[(ultra_timing >> (4*unit)) & ~(0xF0)];

				return 0;

			} else if ((dma_timing) &&

				   ((dma_stat&(1<<(5+unit)))==(1<<(5+unit)))) {

				u8 dmaspeed;



				switch (dma_timing & 0x77) {

				case 0x20:

					dmaspeed = XFER_MW_DMA_2;

					break;

				case 0x21:

					dmaspeed = XFER_MW_DMA_1;

					break;

				case 0x77:

					dmaspeed = XFER_MW_DMA_0;

					break;

				default:

					goto dma_pio;

				}



				drive->current_speed = drive->init_speed = dmaspeed;

				return 0;

			}

dma_pio:

			if (pio_timing) {

				u8 piospeed;



				switch (pio_timing & 0x7f) {

				case 0x20:

					piospeed = XFER_PIO_4;

					break;

				case 0x22:

					piospeed = XFER_PIO_3;

					break;

				case 0x34:

					piospeed = XFER_PIO_2;

					break;

				case 0x47:

					piospeed = XFER_PIO_1;

					break;

				case 0x5d:

					piospeed = XFER_PIO_0;

					break;

				default:

					goto oem_setup_failed;

				}



				drive->current_speed = drive->init_speed = piospeed;

				return 0;

			}

		}

	}



oem_setup_failed:



	pio_timing	= 0;

	dma_timing	= 0;

	ultra_timing	&= ~(0x0F << (4*unit));

	ultra_timing	&= ~(0x0F << (4*unit));

	ultra_enable	&= ~(0x01 << drive->dn);

	ultra_enable	&= ~(0x01 << drive->dn);

	csb5_pio	&= ~(0x0F << (4*drive->dn));

	csb5_pio	&= ~(0x0F << (4*drive->dn));