Re: [PATCH 2/2] mwifiex: print URB submit failure error after threshold attemtps

Hi Kalle,

On Wed, Sep 20, 2017 at 07:30:29AM +0300, Kalle Valo wrote:

Brian Norris [off-list ref] writes:

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Hi Ganapathi,

On Thu, Sep 14, 2017 at 02:14:24PM +0000, Ganapathi Bhat wrote:

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On Thu, 2017-08-31 at 01:21 +0530, Ganapathi Bhat wrote:

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Why not use a ratelimit?

Since this is for receive, the packets are from AP side and we cannot
lower the rate from AP. On some low performance systems this change
will be helpful.

I think Joe was referring to things like printk_ratelimited() or
dev_err_ratelimited(). Those automatically ratelimit prints for you,
using a static counter. You'd just need to make a small warpper for
mwifiex_dbg() using __ratelimit().

Those sort of rate limits are significantly different than yours though.
You were looking to avoid printing errors when there are only a few
failures in a row, whereas the existing rate-limiting infrastructure
looks to avoid printing errors if too many happen in a row. Those are
different goals.

Are you saying that this patch is good to take? Or should Ganapathi
submit v2?

If you're asking me...

All I was saying was that I don't think Joe's suggestion will help
Ganapathi. I'd expect Ganapathi could confirm/deny that part. (Or Joe
could correct me if my interpretation is wrong.)

I'm also not familiar with how we expect dev_alloc_skb() failures to be
handled. If that's a common expected failure mode in low-memory
situations (seems reasonable?) and the driver handles these failure just
fine (completely unreviewed by me, so far; I suspect it doesn't do this
completely correctly), then sure, being less noisy about it as done in
this patch should be fine.

IOW, I don't have concrete feedback for Ganapathi to address, but I'm
not exactly "ack"ing it myself.

Brian