On Mon, 20 Apr 2020 at 07:57, Marek Behun <marek.behun@xxxxxx> wrote: > > On Sun, 19 Apr 2020 07:37:46 +0200 > Marek Behún <marek.behun@xxxxxx> wrote: > > > For some reason the Host Control2 register of the Xenon SDHCI controller > > sometimes reports the bit representing 1.8V signaling as 0 when read > > after it was written as 1. Subsequent read reports 1. > > > > This causes the sdhci_start_signal_voltage_switch function to report > > 1.8V regulator output did not become stable > > > > When CONFIG_PM is enabled, the host is suspended and resumend many > > times, and in each resume the switch to 1.8V is called, and so the > > kernel log reports this message annoyingly often. > > > > Do an empty read of the Host Control2 register in Xenon's > > .voltage_switch method to circumvent this. > > > > Signed-off-by: Marek Behún <marek.behun@xxxxxx> > > I should probably add a Fixes tag here so that it gets backported to > stable versions. Yes, please do. In regards to the comment in the code you added in $subject patch, I would suggest to slim down that quite a bit. More details are available in the commit message, so a few lines should be sufficient, in my opinion. > BTW this happens on Turris Mox. Perhaps add that in the commit message, too. Kind regards Uffe
