Re: [RFC 1/4] iwlwifi: dump stack when fail to gain access to the device

[Stanislaw Gruszka <sgruszka@redhat.com>]

On Mon, Feb 06, 2012 at 08:08:16AM -0800, wwguy wrote:
> On Mon, 2012-02-06 at 17:09 +0100, Stanislaw Gruszka wrote:
> > Print dump stack when the device is not responding. This should give
> > some more clue about the reason of failure. Also change the message we
> > print, since "MAC in deep sleep" is kinda confusing.
> > 
> > On the way add unlikely(), as fail to gain NIC access is hmm ...
> > unlikely.
> > 
> > Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
> > ---
> >  drivers/net/wireless/iwlwifi/iwl-io.c |    6 +++---
> >  1 files changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/net/wireless/iwlwifi/iwl-io.c b/drivers/net/wireless/iwlwifi/iwl-io.c
> > index 83fdff3..ce6d9c1 100644
> > --- a/drivers/net/wireless/iwlwifi/iwl-io.c
> > +++ b/drivers/net/wireless/iwlwifi/iwl-io.c
> > @@ -120,10 +120,10 @@ int iwl_grab_nic_access_silent(struct iwl_bus *bus)
> >  int iwl_grab_nic_access(struct iwl_bus *bus)
> >  {
> >  	int ret = iwl_grab_nic_access_silent(bus);
> > -	if (ret) {
> > +	if (unlikely(ret)) {
> >  		u32 val = iwl_read32(bus, CSR_GP_CNTRL);
> > -		IWL_ERR(bus,
> > -			"MAC is in deep sleep!. CSR_GP_CNTRL = 0x%08X\n", val);
> > +		WARN_ONCE(1, "Timeout waiting for ucode processor access "
> > +			     "(CSR_GP_CNTRL 0x%08x)\n", val);
> >  	}
> >  
> I agree the message and check make sense, but not sure what new clue we
> got by doing this?

Calltrace with very first grab nic access failure.

Stanislaw