Re: [PATCH v3 2/5] firmware: annotate thou shalt not request fw on init or probe

From: Luis R. Rodriguez
Date: Fri Sep 02 2016 - 14:26:18 EST


On Wed, Aug 24, 2016 at 10:17:38AM +0200, Gabriel Paubert wrote:
> On Tue, Aug 23, 2016 at 05:45:04PM -0700, mcgrof@xxxxxxxxxx wrote:
>
> [snip]
> > ---
> > Documentation/firmware_class/README | 20 ++++
> > drivers/base/Kconfig | 2 +-
> > .../request_firmware-avoid-init-probe-init.cocci | 130 +++++++++++++++++++++
> > 3 files changed, 151 insertions(+), 1 deletion(-)
> > create mode 100644 scripts/coccinelle/api/request_firmware-avoid-init-probe-init.cocci
> >
> > diff --git a/Documentation/firmware_class/README b/Documentation/firmware_class/README
> > index cafdca8b3b15..056d1cb9d365 100644
> > --- a/Documentation/firmware_class/README
> > +++ b/Documentation/firmware_class/README
> > @@ -93,6 +93,26 @@
> > user contexts to request firmware asynchronously, but can't be called
> > in atomic contexts.
> >
> > +Requirements:
> > +=============
> > +
> > +You should avoid at all costs requesting firmware on both init and probe paths
> > +of your device driver. Reason for this is the complexity needed to ensure a
> > +firmware will be available for a driver early in boot through different
> > +build configurations. Consider built-in drivers needing firmware early, or
> > +consider a driver assuming it will only get firmware after pivot_root().
> > +
> > +Drivers that really need firmware early should use stuff the firmware in
>
> Minor grammatical nit: s/use//

Fixed, thanks.

Luis