On Wed, Apr 28, 2010 at 8:35 PM, Mike Rapoport <mike@xxxxxxxxxxxxxx> wrote: > Tony Lindgren wrote: >> >> * Mike Rapoport <mike@xxxxxxxxxxxxxx> [100427 00:40]: >>> >>> Tony Lindgren wrote: >>>> >>>> * Mike Rapoport <mike@xxxxxxxxxxxxxx> [100422 01:41]: >>>>> >>>>> Ghorai, Sukumar wrote: >>>>> >>>>> CM-T35, for instance can be assembled with different NAND flash >>>>> chips. Besides, boards that use NAND as primary boot device, we >>>>> anyway depend on proper GPMC configuration in the bootloader chain. >>>>> Having ability to define GPMC timings in the kernel and keep the >>>>> settings made by the bootloader adds flexibility level for board >>>>> designers. >>>> >>>> Not implementing the retime function for GPMC will cause issues >>>> with PM as you cannot scale the L3 frequency without breaking >>>> your GPMC timings. >>> >>> I agree that without retime function scaling the frequency will >>> break the GPMC timings. But my point was that there should be an >>> _option_ to keep the timings defined by the bootloader rather than >>> enforce board files to specify timings. >> >> Sure. Can you please check one more time your patch and what is >> still missing after Stanley's fix? That's now in omap-fixes and master >> branches as commit 11e1ef2d105900a302b7ca92bcaf96a96d0274a1. >> >>> Since skipping the retime function will break gpmc timings in >>> PM-enabled kernel, we need to implement this option in smarter way. >>> E.g. something like: >> >> Yeah we should print some warning if the retime function is not >> implemented as it can cause mysterious bugs later on. I guess >> implementing a dummy retime function would be best as then the >> warning would be related to the actual L3 rate change. > > While working on implementation of gpmc_nand_detect_timings I've seen that > omap2_nand_gpmc_retime converts the timings supplied by the platform to > ticks and passes it to gpmc_cs_set_timings which in turn converts the > timings to ticks. Is it a bug or am I missing something? No, 'omap2_nand_gpmc_retime' does not convert timings supplied by the platform to tick. Rather it rounds the timings passed by the platform to timings in units of 'tick' period. -- Regards, Vimal Singh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
