Re: [PATCH] cxgb4: fix probe when already with invalid parameters

[Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>]

On Wed, Mar 19, 2014 at 09:38:49PM +0000, Dimitrios Michailidis wrote:
> Thadeu Lima de Souza Cascardo wrote:
> > Since commit 636f9d371f70f22961fd598fe18380057518ca31 ("cxgb4: Add
> > support for T4 configuration file"), we have problems when probing the
> > device, and finding out it's already initialized, but does not have
> > valid buffer sizes setup.
> > 
> > This may happen with kexec without shutdown, or bad firmware or
> > bootloader.
> > 
> > The usual symptom is that probe fails:
> > 
> > [    2.605494] cxgb4 0000:50:00.4: Coming up as MASTER: Adapter already
> > initialized
> > [    2.605511] cxgb4 0000:50:00.4: bad SGE FL page buffer sizes [0, 0]
> > [    2.625629] cxgb4: probe of 0000:50:00.4 failed with error -22
> > 
> > The solution is to treat the adapter as not initialized in case the
> > parameters are invalid.
> 
> The patch doesn't look right to me.  Besides reinitializing the device when it finds
> disagreeable settings it disregards that this PF may not be in charge of the device.
> If the controlling PF (what the code calls master) selects values this PF doesn't like
> with the patch it will elevate itself to master and install its own preferences.
> 
> Also not right of course is that FW is claiming the device is initialized when clearly it isn't.
> Can you tell me which FW version is involved here and what steps got the device in this state?
> 

We are trying to netboot, so it's possibly a problem on the Open
Firmware driver that makes it not send FW BYE before handling the CPU to
the bootloader. I could easily reproduce a similar situation by removing
the call to t4_fw_bye during the driver remove path, and reloading the
driver without commit 940d9d34a5467c2e2574866eb009d4cb61e27299 ("cxgb4:
allow large buffer size to have page size").

The firmware I am using is:
firmware-version: 1.9.23.0, TP 0.1.9.1

How about the change below?

If that's OK, I'll send a v2.

Cascardo.


> > Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
> > ---
> >  drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c |   34 +++++++++++++---------
> >  1 files changed, 20 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> > b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> > index 34e2488..d0638f9 100644
> > --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> > +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> > @@ -5237,13 +5237,27 @@ static int adap_init0(struct adapter *adap)
> >  	 * master initialization), note that we're living with existing
> >  	 * adapter parameters.  Otherwise, it's time to try initializing the
> >  	 * adapter ...
> > +	 *
> > +	 * If we're living with non-hard-coded parameters (either from a
> > +	 * Firmware Configuration File or values programmed by a different PF
> > +	 * Driver), give the SGE code a chance to pull in anything that it
> > +	 * needs ...  Note that this must be called after we retrieve our VPD
> > +	 * parameters in order to know how to convert core ticks to seconds.
> >  	 */
> >  	if (state == DEV_STATE_INIT) {
> >  		dev_info(adap->pdev_dev, "Coming up as %s: "\
> >  			 "Adapter already initialized\n",
> >  			 adap->flags & MASTER_PF ? "MASTER" : "SLAVE");
> >  		adap->flags |= USING_SOFT_PARAMS;
> > -	} else {
> > +		ret = t4_sge_init(adap);
> > +		if (ret == -EINVAL) {

-		if (ret == -EINVAL) {
+		if (ret == -EINVAL && adap->flags & MASTER_PF) {

> > +			adap->flags &= ~USING_SOFT_PARAMS;
> > +			state = DEV_STATE_UNINIT;
> > +		} else if (ret < 0) {
> > +			goto bye;
> > +		}
> > +	}
> > +	if (state != DEV_STATE_INIT) {
> >  		dev_info(adap->pdev_dev, "Coming up as MASTER: "\
> >  			 "Initializing adapter\n");
> > 
> > @@ -5300,19 +5314,11 @@ static int adap_init0(struct adapter *adap)
> >  				-ret);
> >  			goto bye;
> >  		}
> > -	}
> > -
> > -	/*
> > -	 * If we're living with non-hard-coded parameters (either from a
> > -	 * Firmware Configuration File or values programmed by a different PF
> > -	 * Driver), give the SGE code a chance to pull in anything that it
> > -	 * needs ...  Note that this must be called after we retrieve our VPD
> > -	 * parameters in order to know how to convert core ticks to seconds.
> > -	 */
> > -	if (adap->flags & USING_SOFT_PARAMS) {
> > -		ret = t4_sge_init(adap);
> > -		if (ret < 0)
> > -			goto bye;
> > +		if (adap->flags & USING_SOFT_PARAMS) {
> > +			ret = t4_sge_init(adap);
> > +			if (ret < 0)
> > +				goto bye;
> > +		}
> >  	}
> > 
> >  	if (is_bypass_device(adap->pdev->device))
> > --
> > 1.7.1
>