On Friday 08 May 2009 15:30:00 Sergei Shtylyov wrote: > Bartlomiej Zolnierkiewicz wrote: > > >>>>>>So you're saying I should support all PIO modes? If so, I would have to > >>>>>>make conditional code, checking perhaps a module param to sort which PIO > >>>>>>mode to use. > > >>>>>If you advertise PIO0-PIO4 as supported the core IDE code will do all the > >>>>>work on figuring which modes are supported by the attached devices. You > >>>>>just need to be able to set them. > > >>>>>Alan > > >>>>Ok, so I've been studying that (I was quite lost for a time, I confess, > >>>>I'm not that much familiar with the IDE subsystem, so please bear with > >>>>me ;-) ). > > >>>>So I need to set up a hook for 'set_pio_mode()', so that when the IDE > >>>>subsystem detects a device and figures the most suitable PIO mode for > >>>>the device, it will call the 'set_pio_mode' routine provided by the > >>>>driver in order to configure the host controller for that PIO mode. > > >>>>This also means that my host controller driver should always default to > >>>>PIO Mode 0, as the initial host controller setup that is carried out by > >>>>the 'init_hwif' routine, allowing devices to be detected. Afterwards, > >>>>the IDE subsystem detects the most suitable PIO mode and calls > >>>>'set_pio_mode' to change that configuration. > > >>>>Am I correct on this? > > >>>Yes! :) > > >>>There is still a room for improvement though -- it would be better to fix > >>>IDE core to set PIO0 before probing devices for all host controllers. > > >>>Moreover it seems that doing it this way would allow us to remove ->init_hwif > >>>method from this driver and do all necessary setup in ep93xx_ide_probe() > >>>(this controller is a single port one so theoretically there shouldn't be > >>>a need for having per-port ->init_hwif implementation). > > >>So, I should remove the 'init_hwif' hook, and all the host controller > >>setup would be made in the driver's probe method, correct? > > > Yes, that would be preferred (of course given that you fix IDE core to do > > initial PIO0 setup first). > > Er, it's not that easy... Think about older CompactFlash cards (and > ancient drives of course) that don't support setting explicit PIO modes > (only the default one) since they don't support IORDY... and also > ide_config_drive_speed() expects drive->id to be already filled in... So I > guess you mean just calling set_pio_mode() prior to probing -- without > setting the drive's own mode? Yes, I mean setting PIO0 _only_ on host. Thanks, Bart -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
