From: Stephen Boyd swboyd@chromium.org
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 --- drivers/base/dd.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -718,7 +718,12 @@ static int really_probe_debug(struct dev 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; }