On 09/15/2016 06:59 AM, Valo, Kalle wrote:
Ben Greear <gree...@candelatech.com> writes:
On 09/14/2016 07:07 AM, Valo, Kalle wrote:
gree...@candelatech.com writes:
From: Ben Greear <gree...@candelatech.com>
When firmware crashes, stack can continue to send packets
for a bit, and existing code was spamming logs.
So, rate-limit the error message for tx failures.
Signed-off-by: Ben Greear <gree...@candelatech.com>
---
drivers/net/wireless/ath/ath10k/mac.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath10k/mac.c
b/drivers/net/wireless/ath/ath10k/mac.c
index cd3016d..42cac32 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -3432,8 +3432,9 @@ static int ath10k_mac_tx_submit(struct ath10k *ar,
}
if (ret) {
- ath10k_warn(ar, "failed to transmit packet, dropping: %d\n",
- ret);
+ if (net_ratelimit())
+ ath10k_warn(ar, "failed to transmit packet, dropping:
%d\n",
+ ret);
ieee80211_free_txskb(ar->hw, skb);
}
ath10k_warn() is already rate limited. If there's something wrong then
that function should be fixed, not the callers.
void ath10k_warn(struct ath10k *ar, const char *fmt, ...)
{
struct va_format vaf = {
.fmt = fmt,
};
va_list args;
va_start(args, fmt);
vaf.va = &args;
dev_warn_ratelimited(ar->dev, "%pV", &vaf);
trace_ath10k_log_warn(ar, &vaf);
va_end(args);
}
The problem with having the ratelimit here is that you may miss
rare warnings due to a flood of common warnings.
That is why it is still useful to ratelimit potential floods
of warnings.
I think this is a common problem in kernel, not specific to ath10k. For
starters you could configure the limits dev_warn_ratelimited() has, not
trying to workaround it in the driver.
I will try to explain this once more.
If you have the ratelimit in a centralized place, then all code that calls it
is rate-limitted with same counter and each call site gets the same priority.
One verbose caller can thus disable logs for the much more rare callers.
My patch pre-filters one of the verbose callers, which lets other more
rare and interesting callers be more likely to print logging messages
that are useful for debugging.
I would like to remove the ratelimit from ath10k_warn eventually.
I think that's not a good idea, it might cause unnecessary host reboots
in problem cases. Rate limitting the messages is much better option.
Ok, but even so, that would be a later patch and that is not a reason
to reject the one I posted.
For what it is worth, I and my users have been running such a patch for years
in various embedded and other systems and it works fine.
Thanks,
Ben
--
Ben Greear <gree...@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
