Hi Jerry, On 12/7/2011 10:23 AM, Huang Changming-R66093 wrote: > >> -----Original Message----- >> From: Hein_Tibosch [mailto:hein_tibosch@xxxxxxxx] >> Sent: Tuesday, December 06, 2011 8:13 PM >> To: Huang Changming-R66093 >> Cc: linux-mmc@xxxxxxxxxxxxxxx; Huang Changming-R66093; Chris Ball >> Subject: Re: [PATCH 2/5 v2] MMC/core: Add f_min to mmc_power_on() >> >> <cut> >>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index >>> a08e6b1..2d40c04 100644 >>> --- a/drivers/mmc/core/core.c >>> +++ b/drivers/mmc/core/core.c >>> @@ -1253,7 +1253,10 @@ static void mmc_power_up(struct mmc_host *host) >>> */ >>> mmc_delay(10); >>> >>> - host->ios.clock = host->f_init; >>> + if (host->f_init) >>> + host->ios.clock = host->f_init; >>> + else >>> + host->ios.clock = host->f_min; >> Are you sure f_min can have a value of zero? >> It should have been set mmc_rescan_try_freq(), when trying a list of >> frequencies: 400000, 300000, 200000, 100000 >> > But, mmc_power_up is called not only by mmc_rescan_try_freq, so the value of f_init may be zero. Ok, I see: mmc_power_up() used to be called only after mmc_rescan_try_freq(), but now you want to call it earlier, because get_cd() *might* need it, even if get_cd is not defined... Still I wonder whether it's good to power-up each and every card: + mmc_power_up(host); if (host->ops->get_cd && host->ops->get_cd(host) == 0) goto out; + mmc_power_off(host); before initialization starts. Remember earlier complaints that f_min is extremely low on some platforms and therefor f_init was introduced. Hein -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
