From: Stephen Boyd <swboyd@chromium.org>
Date: Wed, 12 Apr 2023 15:58:42 -0700
Subject: [PATCH] driver core: Don't require dynamic_debug for initcall_debug
probe timing
References: bsc#1012628
Patch-mainline: 6.3.1
Git-commit: e2f06aa885081e1391916367f53bad984714b4db
commit e2f06aa885081e1391916367f53bad984714b4db upstream.
Don't require the use of dynamic debug (or modification of the kernel to
add a #define DEBUG to the top of this file) to get the printk message
about driver probe timing. This printk is only emitted when
initcall_debug is enabled on the kernel commandline, and it isn't
immediately obvious that you have to do something else to debug boot
timing issues related to driver probe. Add a comment too so it doesn't
get converted back to pr_debug().
Fixes: eb7fbc9fb118 ("driver core: Add missing '\n' in log messages")
Cc: stable <stable@kernel.org>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Brian Norris <briannorris@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230412225842.3196599-1-swboyd@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/base/dd.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 8def2ba0..1b16e0fb 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -708,7 +708,12 @@ static int really_probe_debug(struct device *dev, struct device_driver *drv)
calltime = ktime_get();
ret = really_probe(dev, drv);
rettime = ktime_get();
- pr_debug("probe of %s returned %d after %lld usecs\n",
+ /*
+ * Don't change this to pr_debug() because that requires
+ * CONFIG_DYNAMIC_DEBUG and we want a simple 'initcall_debug' on the
+ * kernel commandline to print this all the time at the debug level.
+ */
+ printk(KERN_DEBUG "probe of %s returned %d after %lld usecs\n",
dev_name(dev), ret, ktime_us_delta(rettime, calltime));
return ret;
}
--
2.35.3