On Sat 21 Nov 12:38 CST 2020, Paul Cercueil wrote: > Hi Mathieu, > > Le ven. 20 nov. 2020 à 15:37, Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> a > écrit : > > Hi Paul, > > > > On Sun, Nov 15, 2020 at 11:50:56AM +0000, Paul Cercueil wrote: > > > Until now the remoteproc core would always default to trying to > > > boot the > > > remote processor at startup. The various remoteproc drivers could > > > however override that setting. > > > > > > Whether or not we want the remote processor to boot, really depends > > > on > > > the nature of the processor itself - a processor built into a WiFi > > > chip > > > will need to be booted for the WiFi hardware to be usable, for > > > instance, > > > but a general-purpose co-processor does not have any predeterminated > > > function, and as such we cannot assume that the OS will want the > > > processor to be booted - yet alone that we have a single do-it-all > > > firmware to load. > > > > > > > If I understand correctly you have various remote processors that use > > the same firmware > > but are serving different purposes - is this correct? > > That's the opposite actually. I have one remote processor which is > general-purpose, and as such userspace may or may not want it started at > boot time - depending on what it wants to do with it. The kernel shouldn't > decide itself whether or not the remote processor should be started, because > that's policy. > > > > > > Add a 'auto_boot' module parameter that instructs the remoteproc > > > whether > > > or not it should auto-boot the remote processor, which will default > > > to > > > "true" to respect the previous behaviour. > > > > > > > Given that the core can't be a module I wonder if this isn't something > > that > > would be better off in the specific platform driver or the device > > tree... Other > > people might have an opinion as well. > > Hardcoded in the platform driver or flagged in the device tree, doesn't > change the fundamental problem - it should be up to the userspace to decide > whether or not the remote processor should boot. > Unfortunately it depends on what you're using your remoteprocs for. And in a system with multiple remoteproc instances I don't think a single global parameter is sufficient - not even a per-driver setting is. I do agree with you that there are types of systems where the decision to auto boot things would happen after the kernel and/or DT has been written. Regards, Bjorn > Cheers, > -Paul > > > > > > Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx> > > > --- > > > drivers/remoteproc/remoteproc_core.c | 7 ++++++- > > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/remoteproc/remoteproc_core.c > > > b/drivers/remoteproc/remoteproc_core.c > > > index dab2c0f5caf0..687b1bfd49db 100644 > > > --- a/drivers/remoteproc/remoteproc_core.c > > > +++ b/drivers/remoteproc/remoteproc_core.c > > > @@ -44,6 +44,11 @@ > > > > > > #define HIGH_BITS_MASK 0xFFFFFFFF00000000ULL > > > > > > +static bool auto_boot = true; > > > +module_param(auto_boot, bool, 0400); > > > +MODULE_PARM_DESC(auto_boot, > > > + "Auto-boot the remote processor [default=true]"); > > > + > > > static DEFINE_MUTEX(rproc_list_mutex); > > > static LIST_HEAD(rproc_list); > > > static struct notifier_block rproc_panic_nb; > > > @@ -2176,7 +2181,7 @@ struct rproc *rproc_alloc(struct device *dev, > > > const char *name, > > > return NULL; > > > > > > rproc->priv = &rproc[1]; > > > - rproc->auto_boot = true; > > > + rproc->auto_boot = auto_boot; > > > rproc->elf_class = ELFCLASSNONE; > > > rproc->elf_machine = EM_NONE; > > > > > > -- > > > 2.29.2 > > > > >
