From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shards.monkeyblade.net (shards.monkeyblade.net [184.105.139.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40Psg75cmnzF1sZ for ; Tue, 17 Apr 2018 01:26:41 +1000 (AEST) Date: Mon, 16 Apr 2018 11:26:36 -0400 (EDT) Message-Id: <20180416.112636.639759764864229205.davem@davemloft.net> To: tlfalcon@linux.vnet.ibm.com Cc: netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, jallen@linux.vnet.ibm.com, nfont@linux.vnet.ibm.com, benh@kernel.crashing.org Subject: Re: [PATCH] ibmvnic: Clear pending interrupt after device reset From: David Miller In-Reply-To: <1523836416-16531-1-git-send-email-tlfalcon@linux.vnet.ibm.com> References: <1523836416-16531-1-git-send-email-tlfalcon@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Thomas Falcon Date: Sun, 15 Apr 2018 18:53:36 -0500 > Due to a firmware bug, the hypervisor can send an interrupt to a > transmit or receive queue just prior to a partition migration, not > allowing the device enough time to handle it and send an EOI. When > the partition migrates, the interrupt is lost but an "EOI-pending" > flag for the interrupt line is still set in firmware. No further > interrupts will be sent until that flag is cleared, effectively > freezing that queue. To workaround this, the driver will disable the > hardware interrupt and send an H_EOI signal prior to re-enabling it. > This will flush the pending EOI and allow the driver to continue > operation. > > Signed-off-by: Thomas Falcon Applied, thanks Thomas.