Hi Niklas,
CC LinusW
On Mon, Jul 2, 2018 at 6:15 PM Niklas Söderlund
<niklas.soderlund@xxxxxxxxxxxx> wrote:
> On 2018-07-02 15:03:02 +0200, Geert Uytterhoeven wrote:
> > CC Sergei,
> >
> > Thanks for your patch!
> >
> > On Mon, Jul 2, 2018 at 10:06 AM Niklas Söderlund
> > <niklas.soderlund+renesas@xxxxxxxxxxxx> wrote:
> > > The datasheet do not document any registers to control drive strength,
> >
> > does
> >
> > > and no drive strength registers are for this reason described for this
> > > SoC. The flag indicating that drive strength can be controlled are
> >
> > flags
> >
> > > however set for some pins in the driver.
> > >
> > > This leads to a NULL pointer dereference when the sh-pfc core tries to
> > > access the struct describing the drive strength registers, for example
> > > when reading the sysfs file pinconf-pins.
> > >
> > > Fix this by removing the SH_PFC_PIN_CFG_DRIVE_STRENGTH from all pins.
> > >
> > > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> >
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> >
> > I'll wait a bit for Sergei's response.
> > Perhaps his version of the datasheet does document drive strength registers?
>
> Do you wish for a v2 addressing the spelling above or can you fix that
> when applying?
Given this fixes a crash, I think this is a fix for v4.18.
So please send a v2 straight to LinusW, with
Fixes: b92ac66a1819602b ("pinctrl: sh-pfc: Add R8A77970 PFC support")
Unfortunately the code has changed since the issue was introduced, so please
send an applicable fix for v4.16/v4.17 to stable after the fix has entered
upstream.
Thanks!
> > > --- a/drivers/pinctrl/sh-pfc/pfc-r8a77970.c
> > > +++ b/drivers/pinctrl/sh-pfc/pfc-r8a77970.c
> > > @@ -21,15 +21,13 @@
> > > #include "core.h"
> > > #include "sh_pfc.h"
> > >
> > > -#define CFG_FLAGS SH_PFC_PIN_CFG_DRIVE_STRENGTH
> > > -
> > > #define CPU_ALL_PORT(fn, sfx) \
> > > - PORT_GP_CFG_22(0, fn, sfx, CFG_FLAGS | SH_PFC_PIN_CFG_IO_VOLTAGE), \
> > > - PORT_GP_CFG_28(1, fn, sfx, CFG_FLAGS), \
> > > - PORT_GP_CFG_17(2, fn, sfx, CFG_FLAGS | SH_PFC_PIN_CFG_IO_VOLTAGE), \
> > > - PORT_GP_CFG_17(3, fn, sfx, CFG_FLAGS | SH_PFC_PIN_CFG_IO_VOLTAGE), \
> > > - PORT_GP_CFG_6(4, fn, sfx, CFG_FLAGS), \
> > > - PORT_GP_CFG_15(5, fn, sfx, CFG_FLAGS)
> > > + PORT_GP_CFG_22(0, fn, sfx, SH_PFC_PIN_CFG_IO_VOLTAGE), \
> > > + PORT_GP_28(1, fn, sfx), \
> > > + PORT_GP_CFG_17(2, fn, sfx, SH_PFC_PIN_CFG_IO_VOLTAGE), \
> > > + PORT_GP_CFG_17(3, fn, sfx, SH_PFC_PIN_CFG_IO_VOLTAGE), \
> > > + PORT_GP_6(4, fn, sfx), \
> > > + PORT_GP_15(5, fn, sfx)
> > > /*
> > > * F_() : just information
> > > * FM() : macro for FN_xxx / xxx_MARK
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
