Re: [PATCH 3/3] staging: octeon: ethernet: add pr_fmt macro

[Ayush Mukkanwar]

On Wed, Mar 25, 2026 at 2:41 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Mar 25, 2026 at 02:33:00PM +0530, Ayush Mukkanwar wrote:
> > On Tue, Mar 24, 2026 at 7:58 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > On Tue, Mar 24, 2026 at 07:00:29PM +0530, AyushMukkanwar wrote:
> > > > Add pr_fmt macro to prefix log messages with the module
> > > > name for easier debugging.
> > > >
> > > > Signed-off-by: AyushMukkanwar <ayushmukkanwar@xxxxxxxxx>
> > > > ---
> > > >  drivers/staging/octeon/ethernet.c | 1 +
> > > >  1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
> > > > index eadb74fc14c8..5bb8c303f88b 100644
> > > > --- a/drivers/staging/octeon/ethernet.c
> > > > +++ b/drivers/staging/octeon/ethernet.c
> > > > @@ -5,6 +5,7 @@
> > > >   * Copyright (c) 2003-2007 Cavium Networks
> > > >   */
> > > >
> > > > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> > > >  #include <linux/platform_device.h>
> > > >  #include <linux/kernel.h>
> > > >  #include <linux/module.h>
> > > > --
> > > > 2.53.0
> > > >
> > >
> > > How about working to remove the existing pr_*() calls with the proper
> > > dev_*() and netdev_*() calls instead, so that pr_fmt() is not needed at
> > > all?  That is the more "correct" solution here.
> > >
> > > thanks,
> > >
> > > greg k-h
> >
> > Hi Greg,
> >
> > After investigating, the pr_*() calls in ethernet-mem.c and
> > ethernet-spi.c are inside functions that only receive hardware pool
> > indices or register structs with no net_device or device pointer
> > available, so dev_*() and netdev_*() replacements are not possible
> > there.
> >
> > For ethernet.c, device pointers are available at most call sites and I
> > can replace those with dev_err() and netdev_err()/netdev_info()
> > appropriately. The two calls where no device pointer is available
> > would keep pr_err() as is.
>
> That's a good start, but for the others, work back up the call chain to
> properly pass in a device pointer so that these warning/error messages
> can get printed out properly.  Drivers should not have any "generic"
> messages like that, as it does not show what device actually created the
> message.
>
> thanks,
>
> greg k-h

Hi Greg,

After tracing the call chains, the pr_warn() calls are inside
ethernet-mem.c. cvm_oct_mem_fill_fpa() which eventually reaches them
is called from two places:

1. ethernet.c via cvm_oct_configure_common_hw(), which is called from
cvm_oct_probe() - pdev is available here.
2. cvm_oct_rx_refill_pool() in ethernet-rx.h, which is called from
cvm_oct_poll() in ethernet-rx.c - no device pointer is available there
as it is called by the NAPI subsystem and oct_rx_group has no device
pointer either.

Since both call sites share cvm_oct_mem_fill_fpa(), adding a struct
device * parameter would break the second call site. The FPA pool is
shared hardware owned by the platform device, so storing &pdev->dev in
a static global during probe and using that in the mem functions in
ethernet-mem.c seems like the right approach. This avoids changing any
function parameters. The same global could also be used for the
pr_err() calls in ethernet-spi.c, where the interrupt handler has no
device pointer available either. Would that be acceptable, or is there
a preferred way to handle this?

Thanks,
Ayush