netdev - Re: [net PATCH 1/1] drivers: net: cpsw: fix disabling of tx interrupt in rx isr

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Message-ID: <20150708073855.GA7277@saruman.tx.rr.com>
Date:	Wed, 8 Jul 2015 02:38:55 -0500
From:	Felipe Balbi <balbi@...com>
To:	Mugunthan V N <mugunthanvnm@...com>
CC:	<netdev@...r.kernel.org>, <davem@...emloft.net>,
	Felipe Balbi <balbi@...com>, <stable@...r.kernel.org>
Subject: Re: [net PATCH 1/1] drivers: net: cpsw: fix disabling of tx
 interrupt in rx isr

Hi,

On Wed, Jul 08, 2015 at 12:17:46PM +0530, Mugunthan V N wrote:
> With the below commit, common isr is split into tx and rx, but in
> rx isr tx interrupt is also disabled. So tx packets are not handled
> during rx interrupts and rx napi completion. Fixing by disabling on
> rx interrupt in rx isr.
> 
> Fixes: c03abd84634d ("net: ethernet: cpsw: don't requests IRQs we don't use")

why does this fix that commit ? What was the regression ? So RX IRQ fire
and both RX and TX are disabled, sure that's bad. But it should cause
lower throughput. At a minimum, I think your commit log needs some work.

Also, disable_irq_nosync() shouldn't really be needed, you could just
mask the IRQ in the IRQ Enable register, but I guess that'd be v4.3
material.

-- 
balbi

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