On Friday 08 May 2009 19:28:22 João Ramos wrote: > > > > > 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 after all this discussion ;-) , my driver will have no 'init_hwif' > method, and the setup code will be on 'ep93xx_ide_probe', which will > configure entirely the IDE host controller. > Moreover, this initial configuration will setup the controller to work > at PIO Mode 0. Later on, the 'set_pio_mode' method will be called and > the controller will configure itself according to the PIO mode reported > by the IDE core. > > Can I proceed this way? Well, yes. Though I hoped that you would at least give a try to fixing IDE core to program PIO0 initially for all host drivers that implement ->set_pio_mode method... > > > >> There's just only one issue; normally, I would setup the specific > >> timings (t0, t1, t2, t2i, etc) in the 'pio_set_mode' hook. However, if > >> you look further in the driver, those timings aren't defined through a > >> memory controller but instead manually enforced by 'ndelay' calls (arghhh). > >> This means that in my low-level procedures for reading and writing, I > >> need to have access to the timings (or the struct ide_timing) > >> corresponding to the PIO mode selected, in order to use the correct delays. > >> > >> My question is: which is the best way to accomplish this? Declaring a > >> global struct ide_timing variable pointer that always holds the correct > >> ide_timing struct to the selected PIO mode? Or should I always check (in > >> some manner) what is the current PIO mode and then select the adequate > >> delays? > >> > > > > I think that the setting variable pointer in ->set_pio_mode method would > > work best. Seems like the existing drive_data field of ide_drive_t is well > > suited for this purpose (however it may be worth to convert it to 'void *' > > type while we are it). > > > > Did you mean 'drive_data' field, or 'driver_data' field? > 'drive_data' field is an unsigned int value; I guess you meant > 'driver_data' field as it is a (void *) field, so I can define it as a > pointer to the correct 'struct ide_timing'. That is why I hinted that you may need to convert 'drive_data' to 'void *' type first. You may also try to use 'driver_data' instead but you will discover rather quickly that you shouldn't do this... ;) 'driver_data' is for use by IDE core and IDE device drivers. 'drive_data' is for use by IDE host drivers. 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
