2014-08-15 10:36 GMT+02:00 Dong, Chuanxiao <chuanxiao.dong@xxxxxxxxx>: > > >> -----Original Message----- >> From: Ulf Hansson [mailto:ulf.hansson@xxxxxxxxxx] >> Sent: Friday, August 15, 2014 4:34 PM >> To: Dong, Chuanxiao >> Cc: linux-mmc; chris@xxxxxxxxxx >> Subject: Re: [PATCH v3] mmc: core: try 1.8v signling in ddr mode if host and >> device >> >> On 15 August 2014 05:28, Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx> >> wrote: >> > Even (e)MMC card can support 3.3v to 1.2v vccq in DDR, but not all >> > host controller can support this, like some of the SDHCI host which >> > connect to an eMMC device. Some of these host controller still needs >> > to use 1.8v vccq for supporting DDR mode. >> > >> > So the sequence will be: >> > if (host and device can both support 1.2v IO) >> > use 1.2v IO; >> > else if (host and device can both support 1.8v IO) >> > use 1.8v IO; >> > so if host and device can only support 3.3v IO, this is the last choice. >> > >> > Signed-off-by: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx> >> > Signed-off-by: Yunpeng Gao <yunpeng.gao@xxxxxxxxx> >> >> This looks good to me! But before I queue it for 3.18 I would appreciate if we >> could get some help in testing this for some various platforms, that support >> MMC DDR. > > Thanks a lot. BTW, this patch is already tested on Intel's platform which can support MMC DDR. This patch associated with vqmmc-supply and vmmc-supply in the DT is working for me too on i.MX6. JM -- 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
