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

Brian Norris [off-list ref] writes:

Hi Ganapathi,

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

quoted

quoted

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

quoted

@@ -300,9 +300,16 @@ static int mwifiex_usb_submit_rx_urb(struct

urb_context *ctx, int size)

quoted

 	if (card->rx_cmd_ep != ctx->ep) {
 		ctx->skb = dev_alloc_skb(size);
 		if (!ctx->skb) {
-			mwifiex_dbg(adapter, ERROR,
-				    "%s: dev_alloc_skb failed\n", __func__);
+			if (++card->rx_urb_failure_count >
+			    MWIFIEX_RX_URB_FAILURE_THRESHOLD) {
+				mwifiex_dbg(adapter, ERROR,
+					    "%s: dev_alloc_skb failed, failure

count = %u\n",

quoted

+					    __func__,
+					    card->rx_urb_failure_count);
+			}
 			return -ENOMEM;

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?

-- 
Kalle Valo