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) > + return ERR_PTR(-EPROBE_DEFER); > + > while (!ret) { > if (!(matches->machine || matches->family || > matches->revision || matches->soc_id)) 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