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) [off-list ref] wrote:

quoted

From: Alice Guo <redacted>

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.

quoted

Signed-off-by: Alice Guo <redacted>

Thanks for your patch!

quoted

--- 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?

quoted

 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