Re: [PATCH v2 01/21] ARM: pxa: magician: Fix Kconfig for magician to always include htc-egpio

Philipp Zabel
2015-08-19T07:29:46Z

Am Dienstag, den 18.08.2015, 22:02 +0200 schrieb Petr Cvek:
> Dne 18.8.2015 v 20:31 Robert Jarzmik napsal(a):
> > Petr Cvek <petr.cvek@tul.cz> writes:
> >
> > > The htc-egpio driver should be always included in the kernel as
> > > it
> > > controls MMC/charging/IrDA power, which is the only way to get
> > > an useful rootfs.
> > >
> > > Signed-off-by: Petr Cvek <petr.cvek@tul.cz>
> > It's already defined in magician_defconfig, why enforce it in
> > Kconfig ?
>
> Good remark, I did not use defconfig at all (as I had to fix from
> zero configuration + I did not know if defconfig works and will be
> supported in the future).
>
> I will check if magician_defconfig needs to be updated (probably for
> leds).
>
> >
> > And if it's enforced and I want to build a kernel for magician
> > without
> > MMC/charging/IrDA, why should I be forced to build in HTC_EGPIO ?
> >
> > Or said differently, does a kernel without HTC_EGPIO is proven to
> > fail 100%
> > without this option ?
>
> Kernel will probably run OK, but the phone will be unusable (for any
> practical purposes). The EGPIO chip (CPLD) will stay in the state
> programmed from the previous environment (bootloader or WinCE/Mobile)
> and drivers fail to init because of the missing EGPIO (and if they
> init, they will be without any idea about state of the peripherals
> (no charger detection/charging current stuck on the previous
> settings, no LCD backlight control, no IrDA, no rootfs, no GSM, no
> sound, no LEDs).
>
> Different PCB revisions probably use EGPIO pin for LCD power (and at
> least on my phone, LCD power must have very specific order).
>
> For future (when ROM XIP will work) I would like to be able boot
> kernel from flash, which itself uses EGPIO for Vpp control (another
> initial EGPIO configuration). Last possible boot is from JTAG and
> there will be no previous EGPIO initialization.
>
> Petr

I agree with Robert, let's drop this patch.

regards
Philipp