On 24 November 2015 at 14:12, Ludovic Desroches <ludovic.desroches@xxxxxxxxx> wrote: > On Tue, Nov 24, 2015 at 12:01:53PM +0100, Ulf Hansson wrote: >> On 24 November 2015 at 10:23, Ludovic Desroches >> <ludovic.desroches@xxxxxxxxx> wrote: >> > Hi Ulf, >> > >> > On Mon, Nov 09, 2015 at 05:30:26PM +0100, Ludovic Desroches wrote: >> >> On Mon, Nov 09, 2015 at 05:00:46PM +0100, Ulf Hansson wrote: >> > >> > [...] >> > >> >> > Now, this discussion was interesting, but I forgot what problem you >> >> > actually where trying to solve? :-) >> >> >> >> There is this discussion because of two things: >> >> - Fixing something I consider as a bug: when I have a VMMC, only >> >> setting/clearing bit 0. Our controller strictly obeys to the spec and >> >> check the 'SD Bus Voltage Select' field. Since we put a reserved value >> >> (000), the Power On is not performed. >> >> - I was trying to get help to understand what is this 'SD Bus Voltage'. >> >> For our controller and sdhci_set_power(), it seems to stand for VMMC. >> >> For me, everything concerning bus voltage is related to VQMMC, so I was >> >> disappointed. >> > >> > Do you plan to take the patch for VMMC? If yes, I will send a new patch >> > for the device tree (I'll only add vmmc, not vqmmc as discussed); if >> > not, forget these two patches. >> > >> >> Which patch do you refer to for "VMMC"? >> > > This one to not write an invalid voltage in the power control register > even if we have an external regulator for vmmc. > As I stated earlier, according to the SDHCI spec in the section for the Power Control Register. Bit 0 needs to be set when communicating with the card as it will for example enable the clock. I suspect if I apply your patch several sdhci variants would break, don't you think? Kind regards Uffe -- 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
