Re: [PATCH] ath10k: Handle "invalid" BDFs for msm8998 devices

From: Simon Horman <simon.horman@netronome.com>
To: Kalle Valo <kvalo@codeaurora.org>
Cc: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>,
	davem@davemloft.net, ath10k@lists.infradead.org,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	MSM <linux-arm-msm@vger.kernel.org>,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ath10k: Handle "invalid" BDFs for msm8998 devices
Date: Wed, 13 Nov 2019 08:00:31 +0100	[thread overview]
Message-ID: <20191113070031.qlikjctfnoxtald5@netronome.com> (raw)
In-Reply-To: <878soks77y.fsf@kamboji.qca.qualcomm.com>

On Wed, Nov 13, 2019 at 06:58:25AM +0200, Kalle Valo wrote:
> Jeffrey Hugo <jeffrey.l.hugo@gmail.com> writes:
> 
> > On Tue, Nov 12, 2019 at 2:04 AM Simon Horman <simon.horman@netronome.com> wrote:
> >>
> >> On Wed, Nov 06, 2019 at 03:47:12PM -0800, Jeffrey Hugo wrote:
> >> > When the BDF download QMI message has the end field set to 1, it signals
> >> > the end of the transfer, and triggers the firmware to do a CRC check.  The
> >> > BDFs for msm8998 devices fail this check, yet the firmware is happy to
> >> > still use the BDF.  It appears that this error is not caught by the
> >> > downstream drive by concidence, therefore there are production devices
> >> > in the field where this issue needs to be handled otherwise we cannot
> >> > support wifi on them.  So, attempt to detect this scenario as best we can
> >> > and treat it as non-fatal.
> >> >
> >> > Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
> >> > ---
> >> >  drivers/net/wireless/ath/ath10k/qmi.c | 11 +++++++----
> >> >  1 file changed, 7 insertions(+), 4 deletions(-)
> >> >
> >> > diff --git a/drivers/net/wireless/ath/ath10k/qmi.c b/drivers/net/wireless/ath/ath10k/qmi.c
> >> > index eb618a2652db..5ff8cfc93778 100644
> >> > --- a/drivers/net/wireless/ath/ath10k/qmi.c
> >> > +++ b/drivers/net/wireless/ath/ath10k/qmi.c
> >> > @@ -265,10 +265,13 @@ static int ath10k_qmi_bdf_dnld_send_sync(struct ath10k_qmi *qmi)
> >> >                       goto out;
> >> >
> >> >               if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
> >> > -                     ath10k_err(ar, "failed to download board data file: %d\n",
> >> > -                                resp.resp.error);
> >> > -                     ret = -EINVAL;
> >> > -                     goto out;
> >> > +                     if (!(req->end == 1 &&
> >> > +                           resp.resp.result == QMI_ERR_MALFORMED_MSG_V01)) {
> >>
> >> Would it make sense to combine the inner and outer condition,
> >> something like this (completely untested) ?
> >
> > I guess, make sense from what perspective?  Looks like the assembly
> > ends up being the same, so it would be down to "readability" which is
> > subjective - I personally don't see a major advantage to one way or
> > the other.  It does look like Kalle already picked up this patch, so
> > I'm guessing that if folks feel your suggestion is superior, then it
> > would need to be a follow on.

My feeling is that it would reduce the churn in the patch making the
patch more readable and likewise improving the readability of the code.
But I do agree this does not affect run-time and I am ambivalent about
updating the patch if it has already been (semi-)accepted.

> 
> Same here, it's only on the pending branch so changes are still
> possible.
> 
> -- 
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches