Messages in this thread | | | Date | Fri, 21 Nov 2014 09:42:08 -0800 | Subject | Re: [PATCH] mmc: dw_mmc: try pick the exact same voltage as vmmc for vqmmc | From | Doug Anderson <> |
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Ulf,
On Fri, Nov 21, 2014 at 4:06 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote: > [...] > >> Sure >> If the first card is sd2.0 since startup, dw_mci_switch_voltage will not be called, > > That can't be right. mmc_power_up() should trigger > dw_mci_switch_voltage() to be invoked.
Hmmm, I think you're right. Addy: can you double check if it's only the 2nd card for you? I was thinking that if a regulator is currently 3.3V and you request 2.7 - 3.3V the regulator framework will treat that as a noop. ...but that definitely doesn't appear to be the case. When I boot up the first time even with no SD card plugged in, I see this at bootup:
[ 3.042234] vccio_sd: 1800 <--> 3300 mV at 3300 mV
...showing that it started at 3.3V. Then I see:
$ grep "" /sys/class/regulator/regulator.16/{name,microvolts} /sys/class/regulator/regulator.16/name:vccio_sd /sys/class/regulator/regulator.16/microvolts:2700000
...so it is certainly getting changed even with no card plugged in.
BTW: I don't actually have one of these failing cards--all of mine work. Addy, do you know the make and model of the card you have that fails?
-Doug
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