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b740d8846e
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: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>