Subject: Re: [PATCH] [v6] net: emac: emac gigabit ethernet controller driver

From: Timur Tabi <[email-masked]>
Date: Wed, 3 Aug 2016 15:00:34 -0500

Timur Tabi wrote:
>
> Is there a good way to test my code? ping and iperf appear to send no
> more than 3 packets at a time, which comes nowhere close to filling the
> queue (which holds 512 normally).  netif_queue_stopped() never returns
> true, no matter what I do.

Never mind, I fixed this problem.  I had a race condition between

	/* update produce idx */
	prod_idx = (tx_q->tpd.produce_idx << tx_q->produce_shift) &
		    tx_q->produce_mask;
	emac_reg_update32(adpt->base + tx_q->produce_reg,
			  tx_q->produce_mask, prod_idx);

and the call to netif_stop_queue().  The emac_reg_update32() signalled 
to the hardware that data is available, and it immediately called the 
ISR, before I had a chance to call netif_stop_queue().  So now I call 
emac_reg_update32() after netif_stop_queue(), and everything works.

I'll post a v7 soon.

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