netdev - Re: [PATCH 2/7] 8139cp: Do not re-enable RX interrupts in cp_tx

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Message-Id: <20150922.164605.1844169715316631068.davem@davemloft.net>
Date:	Tue, 22 Sep 2015 16:46:05 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	dwmw2@...radead.org
Cc:	netdev@...r.kernel.org, romieu@...zoreil.com
Subject: Re: [PATCH 2/7] 8139cp: Do not re-enable RX interrupts in
 cp_tx_timeout()

From: David Woodhouse <dwmw2@...radead.org>
Date: Mon, 21 Sep 2015 15:02:07 +0100

> From: David Woodhouse <David.Woodhouse@...el.com>
> 
> If an RX interrupt was already received but NAPI has not yet run when
> the RX timeout happens, we end up in cp_tx_timeout() with RX interrupts
> already disabled. Blindly re-enabling them will cause an IRQ storm.
> 
> This is somewhat less painful than it was a few minutes ago before I
> fixed the return value from cp_interrupt(), but still suboptimal.
> 
> Unconditionally leave RX interrupts disabled after the reset, and
> schedule NAPI to check the receive ring and re-enable them.
> 
> Signed-off-by: David Woodhouse <David.Woodhouse@...el.com>

As I said, if this makes your IRQ storms go away then therefore it
obviates the need for patch #1.
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