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// > +initramfs or consider using CONFIG_EXTRA_FIRMWARE. Using initramfs is much > +more portable to more distributions as not all distributions wish to enable > +CONFIG_EXTRA_FIRMWARE. Should a driver require the firmware being built-in > +it should depend on CONFIG_EXTRA_FIRMWARE. There is no current annotation for > +requiring a firmware on initramfs. > + > +If you're a maintainer you can help police this with: > + > +$ export COCCI=scripts/coccinelle/api/request_firmware-avoid-init-probe-init.cocci > +$ make coccicheck MODE=report > > about in-kernel persistence: > --------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
