On 2017-05-17 11:02, Fabio Estevam wrote: > Hi Haibo, > > On Tue, May 16, 2017 at 11:10 PM, Bough Chen <haibo.chen@xxxxxxx> wrote: > >> Hi Fabio, >> >> Can you open the mmc debug and show the full log? >> By the way, you should first make sure whether the eMMC chip you used support HS200, and double >> check whether the vccq voltage is 1.8v or 1.2v, HS200 mode can't work on 3.3v I/O voltage. > > The imx7s warp board supplies 3.15V to VCCQ eMMC pins, so it cannot > work in HS200 mode as you said. > > In this case it should still be able to work in DDR52 mode though. Maybe I missed something, but shouldn't that all be part of the device tree these days? E.g. mark that it is only 3.3V capable (no-1-8-v) and maybe other capabilities (see Documentation/devicetree/bindings/mmc/mmc.txt). > > Please see the patch I sent: > http://marc.info/?l=linux-mmc&m=149495763808805&w=2 Afaict, the hardware tries to use whatever is the greatest common denominator... If the board has restrictions, they should be specified in the DT, and the driver should respect them. -- Stefan -- 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
