On Wed, 8 Jun 2022 01:30:42 +0100 Andre Przywara <andre.przyw...@arm.com> wrote:
Hi, > On Tue, 19 Apr 2022 14:27:24 +0200 > Milan P. Stanić <m...@arvanta.net> wrote: > > Hi Milan, > > > [ Please CC to me, I'm not subscribed to mailing list ] > > > > Hi, > > > > On u-boot release 2022.04 keyboard doesn't work in u-boot on Olimex > > TERES-I notebook. > > Thanks for the report, and sorry for the delay! > > > With git bisect I found that commit 35ae126c16a6a9149edc6638faaa247f67b8a400 > > is introduced this. Reverting this commit solved problem and in my test > > keyboard now works. > > Unfortunately just reverting this commit is not really the way forward, > but I had a closer look and few printf's later found the problem: > The USB PHY driver uses the legacy GPIO interface, which is now wrapped > in gpio-uclass.c, to call the actual DM functions. > The commit that you bisected to implements the recommended > .set_flags ops member, which relies on the GPIO being properly > configured before. Unfortunately those compat wrappers seem to be > broken, and not using .set_flags just papered over this problem before: > - A call to gpio_direction_output() fills the DM struct gpio_desc > *locally*, on the stack, so any setup is lost when the function > returns. The GPIO hardware is still configured as an output, but > U-Boot doesn't remember this. > - A call to gpio_direction_output() in the legacy interface is supposed > to also set the output value, but the compat wrapper does not > implement this. Scratch that part: that works, as the h/w routines are called inside dm_gpio_clrset_flags(), where we set the correct flags in our (temporary) struct gpio_desc, before calling the .set_flags implementation. Got tricked by the rather innocent function name. But still calling gpio_direction_output(), then later gpio_set_value() is broken. I guess we should fix it, maybe by forcing GPIOD_IS_OUT in the desc, before calling dm_gpio_set_value()? Cheers, Andre > - When .set_flags is implemented in a GPIO driver implementation, the > DM GPIO interface *requires* GPIOs to be configured before, but > since this information is lot, a call to gpio_set_value() does > nothing. > > So while those issues looks like they demand fixing, in the generic > compat GPIO wrappers, I decided to upgrade the sunxi USB PHY driver to > just use the DM GPIO interface directly. Eventually this driver should > drop the U-Boot configured GPIOs, and use proper DT methods, but this > is a bigger change I'd rather not introduce that late in the > development cycle. > So for now I sent this patch, that should fix the issue: > https://lore.kernel.org/u-boot/20220608000604.3357-1-andre.przyw...@arm.com/ > > If you could please test this patch, then reply to that patch email, > for instance with a Tested-by:, this would be greatly appreciated! > > Cheers, > Andre
