[PATCH] sl82c105: DMA support code cleanup Fold the now equivalent code in the ide_dma_check() method into a mere call to ide_use_dma(). Make config_for_dma() return non-zero if DMA mode has been set and call it from the ide_dma_check() method instead of ide_dma_on(). Also, defer writing the DMA timings to the chip registers until DMA is actually turned on (and do not enable IORDY for DMA). Remove unnecessary code from the init_hwif() method, improve its looks overall, and also rename the driver's ide_dma_check() and dma_start() methods. The patch has been actually tested at last. :-) Note that now this driver can be joined to the ide-use-fast-pio patch. Signed-off-by: Sergei Shtylyov Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/ide/pci/sl82c105.c | 115 +++++++++++++++++---------------------------- 1 file changed, 45 insertions(+), 70 deletions(-) Index: b/drivers/ide/pci/sl82c105.c =================================================================== --- a/drivers/ide/pci/sl82c105.c +++ b/drivers/ide/pci/sl82c105.c @@ -11,6 +11,8 @@ * Merge in Russell's HW workarounds, fix various problems * with the timing registers setup. * -- Benjamin Herrenschmidt (01/11/03) benh@kernel.crashing.org + * + * Copyright (C) 2006-2007 MontaVista Software, Inc. */ #include @@ -115,59 +117,31 @@ static void sl82c105_tune_drive(ide_driv } /* - * Configure the drive and the chipset for DMA ++ * Configure the drive for DMA. ++ * We'll program the chipset only when DMA is actually turned on. */ static int config_for_dma (ide_drive_t *drive) { - ide_hwif_t *hwif = HWIF(drive); - struct pci_dev *dev = hwif->pci_dev; - unsigned int reg; - DBG(("config_for_dma(drive:%s)\n", drive->name)); - reg = (hwif->channel ? 0x4c : 0x44) + (drive->select.b.unit ? 4 : 0); - if (ide_config_drive_speed(drive, XFER_MW_DMA_2) != 0) - return 1; + return 0; - pci_write_config_word(dev, reg, 0x0240); - - return 0; + return ide_dma_enable(drive); } /* - * Check to see if the drive and - * chipset is capable of DMA mode + * Check to see if the drive and chipset are capable of DMA mode. */ - -static int sl82c105_check_drive (ide_drive_t *drive) +static int sl82c105_ide_dma_check (ide_drive_t *drive) { - ide_hwif_t *hwif = HWIF(drive); - - DBG(("sl82c105_check_drive(drive:%s)\n", drive->name)); - - do { - struct hd_driveid *id = drive->id; + struct hd_driveid *id = drive->id; - if (!drive->autodma) - break; + DBG(("sl82c105_ide_dma_check(drive:%s)\n", drive->name)); - if (!id || !(id->capability & 1)) - break; - - /* Consult the list of known "bad" drives */ - if (__ide_dma_bad_drive(drive)) - break; - - if (id->field_valid & 2) { - if ((id->dma_mword & hwif->mwdma_mask) || - (id->dma_1word & hwif->swdma_mask)) - return 0; - } - - if (__ide_dma_good_drive(drive) && id->eide_dma_time < 150) - return 0; - } while (0); + if (drive->autodma && (id->capability & 1) && + ide_use_dma(drive) && config_for_dma(drive)) + return 0; return -1; } @@ -236,7 +210,7 @@ static int sl82c105_ide_dma_lost_irq(ide * The generic IDE core will have disabled the BMEN bit before this * function is called. */ -static void sl82c105_ide_dma_start(ide_drive_t *drive) +static void sl82c105_dma_start(ide_drive_t *drive) { ide_hwif_t *hwif = HWIF(drive); struct pci_dev *dev = hwif->pci_dev; @@ -258,12 +232,18 @@ static int sl82c105_ide_dma_timeout(ide_ static int sl82c105_ide_dma_on (ide_drive_t *drive) { + struct pci_dev *dev = HWIF(drive)->pci_dev; + int rc, reg = 0x44 + drive->dn * 4; + DBG(("sl82c105_ide_dma_on(drive:%s)\n", drive->name)); - if (config_for_dma(drive)) - return 1; - printk(KERN_INFO "%s: DMA enabled\n", drive->name); - return __ide_dma_on(drive); + rc = __ide_dma_on(drive); + if (rc == 0) { + pci_write_config_word(dev, reg, 0x0200); + + printk(KERN_INFO "%s: DMA enabled\n", drive->name); + } + return rc; } static void sl82c105_dma_off_quietly(ide_drive_t *drive) @@ -376,7 +356,7 @@ static unsigned int __devinit init_chips } /* - * Initialise the chip + * Initialise IDE channel */ static void __devinit init_hwif_sl82c105(ide_hwif_t *hwif) { @@ -396,11 +376,6 @@ static void __devinit init_hwif_sl82c105 hwif->drives[0].drive_data = hwif->drives[1].drive_data = 0x0909; hwif->drives[0].autotune = hwif->drives[1].autotune = 1; - hwif->atapi_dma = 0; - hwif->mwdma_mask = 0; - hwif->swdma_mask = 0; - hwif->autodma = 0; - if (!hwif->dma_base) return; @@ -410,27 +385,27 @@ static void __devinit init_hwif_sl82c105 * Never ever EVER under any circumstances enable * DMA when the bridge is this old. */ - printk(" %s: Winbond 553 bridge revision %d, BM-DMA disabled\n", - hwif->name, rev); - } else { - hwif->atapi_dma = 1; - hwif->mwdma_mask = 0x04; - - hwif->ide_dma_check = &sl82c105_check_drive; - hwif->ide_dma_on = &sl82c105_ide_dma_on; - hwif->dma_off_quietly = &sl82c105_dma_off_quietly; - hwif->ide_dma_lostirq = &sl82c105_ide_dma_lost_irq; - hwif->dma_start = &sl82c105_ide_dma_start; - hwif->ide_dma_timeout = &sl82c105_ide_dma_timeout; - - if (!noautodma) - hwif->autodma = 1; - hwif->drives[0].autodma = hwif->autodma; - hwif->drives[1].autodma = hwif->autodma; - - if (hwif->mate) - hwif->serialized = hwif->mate->serialized = 1; + printk(" %s: Winbond W83C553 bridge revision %d, " + "BM-DMA disabled\n", hwif->name, rev); + return; } + + hwif->atapi_dma = 1; + hwif->mwdma_mask = 0x04; + + hwif->ide_dma_check = &sl82c105_ide_dma_check; + hwif->ide_dma_on = &sl82c105_ide_dma_on; + hwif->dma_off_quietly = &sl82c105_dma_off_quietly; + hwif->ide_dma_lostirq = &sl82c105_ide_dma_lost_irq; + hwif->dma_start = &sl82c105_dma_start; + hwif->ide_dma_timeout = &sl82c105_ide_dma_timeout; + + if (!noautodma) + hwif->autodma = 1; + hwif->drives[0].autodma = hwif->drives[1].autodma = hwif->autodma; + + if (hwif->mate) + hwif->serialized = hwif->mate->serialized = 1; } static ide_pci_device_t sl82c105_chipset __devinitdata = {