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Subject: Re: [PATCH v1 0/2] fpga: dfl: Log and clear errors on driver init
To:     "Wu, Hao" <hao.wu@intel.com>, "mdf@kernel.org" <mdf@kernel.org>,
        "linux-fpga@vger.kernel.org" <linux-fpga@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     "trix@redhat.com" <trix@redhat.com>,
        "lgoncalv@redhat.com" <lgoncalv@redhat.com>,
        "Xu, Yilun" <yilun.xu@intel.com>,
        "Gerlach, Matthew" <matthew.gerlach@intel.com>
References: <20211019231545.47118-1-russell.h.weight@intel.com>
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From:   Russ Weight <russell.h.weight@intel.com>
Message-ID: <f64249d2-1d48-c191-bce8-5e9e4a5e4643@intel.com>
Date:   Wed, 20 Oct 2021 17:05:52 -0700
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On 10/19/21 9:44 PM, Wu, Hao wrote:
>> Subject: [PATCH v1 0/2] fpga: dfl: Log and clear errors on driver init
>>
>> These patches address a request to log and clear any prexisting errors on
>> FPGA cards when the drivers load. Any existing errors will result in print
>> statements to the kernel error log before the errors are cleared. These
>> changes specifically affect the fme and port error registers.
> Could you please explain more about why we need this change? 
> As we have user interface to log and clear errors already, is it a better choice
> to let userspace log and clear them during AFU initialization?
In the new architecture we are offering more flexibility to customers
for adding functions. With these designs it becomes nearly impossible
to design the AFU interface handler to recover from errors and resume
operation afterwards. The proposed solution is to flag the source of
the error and then capture it in sticky registers so that they can be
read out from SW in the event of a crash/warm boot. To ensure that we
capture these errors, the proposal is to log them in the kernel log and
clear them at driver initialization.

- Russ

> Hao
>
>> Russ Weight (2):
>>   fpga: dfl: afu: Clear port errors in afu init
>>   fpga: dfl: fme: Clear fme global errors at driver init
>>
>>  drivers/fpga/dfl-afu-error.c |  26 ++++---
>>  drivers/fpga/dfl-fme-error.c | 128 +++++++++++++++++++++++------------
>>  2 files changed, 100 insertions(+), 54 deletions(-)
>>
>> --
>> 2.25.1