On Tue, Nov 24, 2015 at 02:56:21PM +0100, Ulf Hansson wrote: > 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 am okay with bit 0. I don't want to change this part, it will be done later in sdhci_set_power(). My concern is only about bit 3-1, I want to go through the switch statement. > I suspect if I apply your patch several sdhci variants would break, > don't you think? I wouldn't sign it with my blood but I don't think so. It seems they don't care about the SD bus Voltage since they work with an unsupported voltage. Regards Ludovic -- 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
