From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 2/2] sh_eth: workaround for spurious ECI interrupt Date: Sun, 31 Mar 2013 19:44:48 -0400 (EDT) Message-ID: <20130331.194448.1126574548002783274.davem@davemloft.net> References: <201303312354.20695.sergei.shtylyov@cogentembedded.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, nobuhiro.iwamatsu.yj@renesas.com, linux-sh@vger.kernel.org To: sergei.shtylyov@cogentembedded.com Return-path: In-Reply-To: <201303312354.20695.sergei.shtylyov@cogentembedded.com> Sender: linux-sh-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Sergei Shtylyov Date: Sun, 31 Mar 2013 23:54:20 +0400 > At least on Renesas R8A7778, EESR.ECI interrupt seems to fire regardless of its > mask in EESIPR register. I can 100% reproduce it with the following scenario: > target is booted with 'ip=on' option, and so IP-Config opens SoC Ether device > but doesn't get a proper reply and then succeeds with on-board SMC chip; then > I login and try to bring up the SoC Ether device with 'ifconfig', and I get > an ECI interrupt once request_irq() is called by sh_eth_open() (while interrupt > mask in EESIPR register is all 0), if that interrupt is accompanied by a pending > EESR.FRC (frame receive completion) interrupt, I get kernel oops in sh_eth_rx() > because sh_eth_ring_init() hasn't been called yet! > > The solution I worked out is the following: in sh_eth_interrupt(), mask the > interrupt status from EESR register with the interrupt mask from EESIPR register > in order not to handle the disabled interrupts -- but forcing EESIPR.M_ECI bit > in this mask set because we always need to fully handle EESR.ECI interrupt in > sh_eth_error() in order to quench it (as it doesn't get cleared by just writing > 1 to the this bit as all the other interrupts). > > While at it, remove unneeded initializer for 'intr_status' variable and give it > *unsigned long* type, matching the type of sh_eth_read()'s result; fix comment. > > Signed-off-by: Sergei Shtylyov > Reviewed-by: Max Filippov Applied.