This patch is based on the documentation (I would like to thank Promise
for it) and also partially on the older vendor driver.
Rewrite mode programming code:
* disable 66MHz clock in pdc202xx_tune_chipset() so it is correctly disabled
even if both devices on the channel are not DMA capable and after reset
* enable/disable IORDY and PREFETCH bits in pdc202xx_tune_chipset()
as they need to be setup correctly also for PIO only devices, plus IORDY
wasn't disabled for non-IORDY devices and PREFETCH wasn't disabled for
ATAPI devices
* remove dead code for setting SYNC_ERDDY_EN bits from config_chipset_for_dma()
(driver sets ->autotune to 1 so PIO modes are always programmed => lower
nibble of register A never equals 4 => "chipset_is_set" is always true)
* enable PIO mode programming for all ATAPI devices
(it was limited to ->media == ide_cdrom devices)
* remove extra reads of registers A/B/C, don't read register D et all
* do clearing / programming of registers A/B/C in one go
(gets rid of extra PCI config space read/write cycle)
* set initial values of drive_conf/AP/BP/CP variables to zero
(paranoia for the case when PCI reads fail)
* remove XFER_UDMA6 to XFER_UDMA5 remapping case - it can't happen
(ide_rate_filter() takes care of it)
* fix XFER_MW_DMA0 timings (they were overclocked, use the official ones)
* fix bitmasks for clearing bits of register B:
- when programming DMA mode bit 0x10 of register B was cleared which
resulted in overclocked PIO timing setting (iff PIO0 was used)
- when programming PIO mode bits 0x18 weren't cleared so suboptimal
timings were used for PIO1-4 if PIO0 was previously set (bit 0x10)
and for PIO0/3/4 if PIO1/2 was previously set (bit 0x08)
* add FIXME comment about missing locking for 66MHz clock register
Also while at it:
* remove unused defines
* do a few cosmetic / CodingStyle fixes
* bump driver version
v2:
* in pdc202xx_tune_chipset() the old content of drive configuration
registers is used only by the debugging code so cover "drive_conf"
PCI registers read by #if PDC202XX_DEBUG_DRIVE_INFO
(Noticed by Sergei Shtylyov)
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
4fce3164b8