SDHC errors during boot on RPi2 (11.0-CURRENT)

[Ian Lepore]

On Thu, 2015-07-16 at 21:57 -0600, Warner Losh wrote:
> > On Jul 16, 2015, at 12:55 PM, Ian Lepore <ian at FreeBSD.org> wrote:
> > 
> > On Thu, 2015-07-16 at 15:17 -0300, Luiz Otavio O Souza wrote:
> >> On 16 July 2015 at 09:23, Andreas Schwarz wrote:
> >>> On Wed, 15 Jul 2015 21:17:21 -0600
> >>> Warner Losh wrote:
> >>> 
> >>>>> On Jul 14, 2015, at 6:06 PM, Dan Raymond wrote:
> >>>>> 
> >>>>> Is anyone else getting these errors during every boot?  I'm running r285346.
> >>>> 
> >>>> I’ve been running on the RPi2 for some time and have never seen this. I haven’t
> >>>> rebuild in the past few weeks though.
> >>>> 
> >>>> Does this happen on either SD cards? Or other versions of the kernel?
> >>> 
> >>> I've the same output (using generic RPI2 kernel conf).
> >> 
> >> This is a side effect of r283128, if you comment that line that
> >> re-select the card, CMD7 won't fail.
> >> 
> >> This also affects the MMC controller on Allwinner SoCs.
> > 
> > Hmm, so some cards deselect themselves when they shouldn't, and our
> > workaround that reselects them fails if the card didn't deselect itself.
> > Maybe it will work for all cards/controllers if we explicitly deselect
> > then reselect the card at that point.  (This only happens once at
> > card-insert/boot time, so it shouldn't impact performance.)
> > 
> > The attached patch adds the explicit deselect; it may or may not help.
> > (I haven't tested this at all).
> > 
> > -- Ian
> > 
> > Index: mmc.c
> > ===================================================================
> > --- mmc.c	(revision 285419)
> > +++ mmc.c	(working copy)
> > @@ -1392,6 +1392,7 @@ mmc_discover_cards(struct mmc_softc *sc)
> > 			 * out. Others seem to handle it correctly, so it may
> > 			 * be a combination of card and controller.
> > 			 */
> > +			mmc_select_card(sc, 0);
> > 			mmc_select_card(sc, ivar->rca);
> > 			mmc_app_sd_status(sc, ivar->rca, ivar->raw_sd_status);
> > 			mmc_app_decode_sd_status(ivar->raw_sd_status,
> 
> Yes. I like this. Update the comment though please.
> 
> Warner
> 

Yeah, when I commit I'll make the comment match the new reality, just
waiting to hear another success report or two first.

-- Ian