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

From: Casey Leedom <[email-masked]>
Date: Wed, 19 Mar 2014 15:13:10 -0700

Okay, that firmware is recent enough but Dimitris is right, the patch 
has a ton of problems.  This section of code is very tricky and we've 
worked hard to get it right.  The firmware also has special code in it 
to ~try to catch~ cases where a previous driver on the same PF failed to 
issue a BYE command.  When the firmware sees a new HELLO command come in 
from a PF and that PF is already "registered" (via a previous HELLO 
command), if it's the _only_ PF "registered" and the new HELLO command 
provides the Clear Initialized flag, then the firmware will assume a 
missing BYE and automatically "de-initialize" the firmware/chip.  So 
it's Very Weird that you're getting a PF is MASTER and Chip/Firmware is 
Initialized return.

Casey

On 03/19/14 14:57, Thadeu Lima de Souza Cascardo wrote:
> 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 <[email-masked]>
>>> ---
>>>   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