On Mon, Oct 20, 2014 at 08:26:55PM +0100, Doug Anderson wrote: > Mark, > > On Mon, Oct 20, 2014 at 11:41 AM, Mark Rutland <mark.rutland@xxxxxxx> wrote: > > On Mon, Oct 20, 2014 at 04:31:18PM +0100, dinguyen@xxxxxxxxxxxxxxxxxxxxx wrote: > >> From: Dinh Nguyen <dinguyen@xxxxxxxxxxxxxxxxxxxxx> > >> > >> Without this patch, the booting the SOCFPGA platform would hang at the > >> SDMMC driver loading. There were 2 patches that caused this to happen: > >> > >> - Patch 9795a846e10 "mmc: dw_mmc: remove dw_mci_of_cd_gpio/wp_gpio()" removed > >> looking for "cd-gpios", since mmc_of_parse was getting called. > >> - Patch 3cf890fc42b "mmc: dw_mmc: Pass back errors from mmc_of_parse()" would > >> hang the system at the SDMMC driver loading. > > > > Regardless of which patches caused the issue, the existing DTB should > > continue to function. This is a kernel bug, not a DTB bug. > > Right. The kernel bug is that there is no "dtb fixup" stage of the > kernel to fix up old dtbs with this dtb bug. > > Said another way: > > 1. The old dtb was (possibly) not specifying the cd-gpio properly. > > 2. The kernel had a bug where it was ignoring that error. Things may > have been working because of some other side effect (maybe polling was > working). > > 3. If we fix the kernel bug, what should we do? The only sensible > thing (if we need to support old DTB with no changes) is to add a DTB > fixup stage. > > ...or did someone add that stage and I missed it? Unfortunately, we have no generic DTB fixup stage currently. What exactly was wrong with this cd-gpios description that previously allowed it to function? Can we not print a warning and fall back to the old behaviour in this case? Thanks, Mark -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
