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SubjectRe: [PATCH v2] firmware loader: log path to loaded firmwares
On Wed, Nov 13, 2019 at 12:56:28AM +0000, Luis Chamberlain wrote:
> On Sun, Nov 03, 2019 at 01:06:46PM -0500, Drew DeVault wrote:
> >
> > This is useful for users who are trying to identify the firmwares in use
> > on their system.
> >
> > Signed-off-by: Drew DeVault <>
> > ---
> > v2 uses dev_dbg instead of printk(KERN_INFO)
> >
> > drivers/base/firmware_loader/main.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
> > index bf44c79beae9..2537da43a572 100644
> > --- a/drivers/base/firmware_loader/main.c
> > +++ b/drivers/base/firmware_loader/main.c
> > @@ -504,6 +504,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
> > path);
> > continue;
> > }
> > + dev_dbg(device, "Loading firmware from %s\n", path);
> Because this is dev_dbg() I'm willing to consider it, so that its not
> always enabled. However its not in the right place, the code path you
> are addressing is only for direct filesystem lookups. If that fails
> some systems do a fallback call out to userspace. To cover both cases,
> you want it at the end of _request_firmware() on the success path. Can
> you send a new patch?
As the author of a separate patch that predates Drew's patch (originally
in July, with a later version sent to the list last week): (v1) (v2)

This already uses the _request_firmware path to fire after the firmware
was successfully loaded. The commit message is also specific that it's
to cover early boot situations, before UEVENT can be logged.

dev_dbg means that the loglevel must have been set to debug BEFORE the
firmware load took place, but this means either setting system-wide
debug spam or requiring debugfs, which is annoying for boot stuff (not
impossible, just annoying).

I have two uses cases overall:
- log so you know exactly when it's loaded successfully (great if
loading a firmware causes your system to lock up a few seconds later)
- at some point in the future, being able to query what firmware was
loaded in the past, and esp. exactly what version/data was in that
firmware file.
Robin Hugh Johnson
Gentoo Linux: Dev, Infra Lead, Foundation Treasurer
E-Mail :
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