On 25 August 2015 at 14:20, Joakim Tjernlund <joakim.tjernl...@transmode.se> wrote: > On Tue, 2015-08-25 at 14:05 +0200, Ulf Hansson wrote: >> On 10 August 2015 at 18:50, Joakim Tjernlund >> <joakim.tjernl...@transmode.se> wrote: >> > in mmc_power_up() we have: >> > /* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v >> > */ >> > if (__mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330) == 0) >> > dev_err(mmc_dev(host), "Initial signal voltage of 3.3v\n"); >> > else if (__mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180) == >> > 0) >> > dev_err(mmc_dev(host), "Initial signal voltage of 1.8v\n"); >> > else if (__mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120) == >> > 0) >> > dev_err(mmc_dev(host), "Initial signal voltage of 1.2v\n"); >> > >> > Here one jut brutally tries to set the initial power to 3.3 but nowhere in >> > general code there is a check if the controller can handle this w.r.t >> > HOST CAPS. >> >> You are right, it's brutal. :-) >> >> Perhaps the host driver should return -EINVAL when a voltage level >> can't be reached. The above code should not print messages as errors, >> at least as long some voltage level can be used. >> >> > Where should this check be performed, I am guessing either here or in >> > sdhci? >> > This is all new to me so I am just throwing this out there >> >> Do you want to send a patch? > > No, you didn't answer the question
Sorry for being a bit vague. I looked a bit more into this. Currently drivers return error codes according to when they can't set the requested voltage level, so that's all fine - right? Moreover, the above code snippet is modified by you (or someone else) locally, since in the upstream version of the code, the prints are done a debug level. That's also okay, I think. Perhaps changing the last print to warn level instead, since reaching that point would mean all attempts have failed. Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
