On 28/05/20 4:12 pm, Serge Semin wrote: [...] >>> + >>> +static map_word __xipram bt1_rom_dummy_read(struct map_info *map, >>> + unsigned long ofs) >>> +{ >>> + map_word ret; >>> + >>> + ret.x[0] = 0xFF; >>> + >>> + return ret; >>> +} >> Why define dummy_io for "baikal,bt1-boot-rom"? I don't see any use of >> adding a driver that always reads 0xFFs > This is supposed to be temporary solution for the baikal,bt1-boot-rom ROM. > The Boot ROM mirror might reflect either an embedded firmware or the SPI flash > directly mapped into the memory. In former case there is no problem, we can > freely read from the Boot ROM region. But in the later case the mirrored region > (memory mapped SPI flash) is not always accessible. If normal Boot SPI > controller is enabled, then the SPI flash mapping isn't accessible (any attempt > will cause a bus-error). In order to fix this we'd need a mutual exclusive lock, > which would disable the SPI controller while the mirrored memory mapped SPI flash > region needs to be accessed. Such mechanism isn't currently implemented, but it > will in be in the framework of my patch created for the SPI subsystem. > > My idea was to just provide a dummy callback for now and replace it with normal > IO-methods with mutual exclusive lock-unlocks when the corresponding SPI driver > is accepted. > Yes I understand, but I don't see any advantage for end user by providing dummy calls... So please don't add the callbacks until they implement proper functionality ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/