Messages in this thread | | | Date | Mon, 13 Feb 2006 23:35:31 +0100 | From | Bartlomiej Zolnierkiewicz <> | Subject | Re: RFC: Compact Flash True IDE Mode Driver |
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On 2/13/06, Kumar Gala <galak@kernel.crashing.org> wrote: > > On Feb 13, 2006, at 2:21 PM, Bartlomiej Zolnierkiewicz wrote: > > > On 2/13/06, Kumar Gala <galak@kernel.crashing.org> wrote: > >> > >> On Feb 13, 2006, at 10:53 AM, Bartlomiej Zolnierkiewicz wrote: > >> > >>> On 2/13/06, Kumar Gala <galak@kernel.crashing.org> wrote: > >>> > >>>>>> +static void cfide_outsl(unsigned long port, void *addr, u32 > >>>>>> count) > >>>>>> +{ > >>>>>> + panic("outsl unsupported"); > >>>>>> +} > >>>>> > >>>>> This will panic as soon as somebody tries to enable 32-bit I/O > >>>>> using hdparm. Please add ide_hwif_t.no_io_32bit flag and teach > >>>>> ide-disk.c:ide_disk_setup() about it (separate patch). > >>>> > >>>> I'm not sure I follow this, can you expand. > >>> > >>> Do "hdparm -c 2 /dev/hdx" first and then read/write to the device > >>> and you should see it. :) > >>> > >>> We need to make "hdparm -c 2" (and "hdparm -c 3") unsupported > >>> (see how "io_32bit" setting is handled in ide_add_generic_settings() > >>> and how it can be read-only or read-write setting depending on the > >>> value of drive->no_io_32bit). > >>> > >>> To do this we need to set drive->no_io_32bit to 1 (see how > >>> ide_disk_setup() handles it). Unfortunately 32-bit I/O capability > >>> is based on capabilities of both host and device so we have to > >>> add new flag hwif->no_io_32bit to indicate that host doesn't > >>> support 32-bit I/O. > >> > >> This all make sense, should I check for hwif->no_io_32bit in > >> idedisk_setup() and set drive->no_io_32bit to 1 if hwif->no_io_32bit > >> is 1 or do this the test in ide_add_generic_settings()? > > > > Good question. idedisk_setup() seems more logical but in the current > > model "io_32bit" setting is still accessible without ide-disk > > driver through > > /proc/ide/ interface so... > > > > Moreover the current drive->no_io_32bit code in ide-disk is wrong: > > * it shouldn't be overriding drive->no_io_32bit flag if it is 1 > > * doing this in ide-disk may be too late w.r.t. > > ide_add_generic_settings() > > > > Therefore your previous suggestion is the right one - the best place > > to deal with ->no_io_32bit is ide-probe.c - doing this for all > > drives at > > the end of probe_hwif() should fix all above issues. > > Now I'm confused. If I understand the code, what I want is for the > "io_32bit" setting to have its RW field set to SETTING_READ, such > that drive->no_io_32bit can NOT be changed. Additionally, I want it > set to 1 if hwif->no_io_32bit is 1.
Yes.
> Are you saying that at the end of probe_hwif() I should iterate over > the drives for that hwif and set drive->no_io_32bit to 1 if hwif- > >no_io_32bit is 1? If so, can I do this in the last loop that > already exists that iterates over the drives?
Well, no - this loop is for tuning and is already over-complicated.
> Will I not also want to test hwif->no_io_32bit in idedisk_setup() to > ensure that it can only set driver->no_io_32bit to 0 if hwif- > >no_io32bit is 0?
No, you want to move this code to ide-probe.c because of the reason given in my last mail: setting drive->no_io_32bit in ide-disk is too late w.r.t. ide_add_generic_settings():
init_gendisk()->hwif_init()->ide_add_generic_settings()
so drive->no_io_32bit flag needs to be set earlier (probe_hwif() is OK).
And yes, this IDE stuff is complicated... :)
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