On Mon, Apr 19, 2021 at 10:20:13AM +0200, Geert Uytterhoeven wrote: > Hi Alice, > > CC Arnd (soc_device_match() author) > > On Mon, Apr 19, 2021 at 6:28 AM Alice Guo (OSS) <alice.guo@xxxxxxxxxxx> wrote: > > From: Alice Guo <alice.guo@xxxxxxx> > > > > In i.MX8M boards, the registration of SoC device is later than caam > > driver which needs it. Caam driver needs soc_device_match to provide > > -EPROBE_DEFER when no SoC device is registered and no > > early_soc_dev_attr. > > I'm wondering if this is really a good idea: soc_device_match() is a > last-resort low-level check, and IMHO should be made available early on, > so there is no need for -EPROBE_DEFER. > > > > > Signed-off-by: Alice Guo <alice.guo@xxxxxxx> > > Thanks for your patch! > > > --- a/drivers/base/soc.c > > +++ b/drivers/base/soc.c > > @@ -110,6 +110,7 @@ static void soc_release(struct device *dev) > > } > > > > static struct soc_device_attribute *early_soc_dev_attr; > > +static bool soc_dev_attr_init_done = false; > > Do you need this variable? > > > > > struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr) > > { > > @@ -157,6 +158,7 @@ struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr > > return ERR_PTR(ret); > > } > > > > + soc_dev_attr_init_done = true; > > return soc_dev; > > > > out3: > > @@ -246,6 +248,9 @@ const struct soc_device_attribute *soc_device_match( > > if (!matches) > > return NULL; > > > > + if (!soc_dev_attr_init_done && !early_soc_dev_attr) > > if (!soc_bus_type.p && !early_soc_dev_attr) There is one place checking this already. We could wrap it in a helper function: static bool device_init_done(void) { return soc_bus_type.p ? true : false; } regards, dan carpenter