Return-path: Received: from mail-sn1nam02on0089.outbound.protection.outlook.com ([104.47.36.89]:61733 "EHLO NAM02-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752422AbdATOOY (ORCPT ); Fri, 20 Jan 2017 09:14:24 -0500 From: Bharat Kumar Gogada To: Larry Finger , "chaoming_li@realsil.com.cn" , "linux-wireless@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: "kvalo@codeaurora.org" , "netdev@vger.kernel.org" , Ravikiran Gummaluri Subject: RE: [PATCH] rtlwifi: rtl8192x: Enabling and disabling hardware interrupts after enabling local irq flags Date: Fri, 20 Jan 2017 14:14:10 +0000 Message-ID: <8520D5D51A55D047800579B094147198263CA86D@XAP-PVEXMBX02.xlnx.xilinx.com> (sfid-20170120_151441_420878_7F228CE3) References: <1484820854-16719-1-git-send-email-bharatku@xilinx.com> In-Reply-To: Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: > On 01/19/2017 04:14 AM, Bharat Kumar Gogada wrote: > > -Realtek 8192CE chipset maintains local irq flags after enabling/disabl= ing > > hardware interrupts. > > -Hardware interrupts are enabled before enabling the local irq > > flags(these flags are being checked in interrupt handler), > > leading to race condition on some RP, where the irq line between > > bridge and GIC goes high at ASSERT_INTx and goes low only > > at DEASSERT_INTx. In this kind of RP by the time ASSERT_INTx is seen > > irq_enable flag is still set to false, resulting in continuous > > interrupts seen by CPU as DEASSERT_INTx cannot be sent since > > flag is still false and making CPU stall. > > -Changing the sequence of setting these irq flags. > > > > Signed-off-by: Bharat Kumar Gogada > > --- >=20 > This patch should be enhanced with the smb_xx() calls as suggested by by = Lino. >=20 > The subject should be changed. I would suggest something like "rtlwifi: > rtl8192ce: Prevent race condition when enabling interrupts", as it explai= ns the > condition you are preventing. >=20 > The other PCI drivers also have the same problem. Do you want to prepare = the > patches, or should I do it? >=20 Thanks Larry. Please send out the patches adding the above enhancements sug= gested by Lino. Bharat