From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DE81C4727F for ; Tue, 29 Sep 2020 12:09:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE8BD20684 for ; Tue, 29 Sep 2020 12:09:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601381392; bh=LJr5lMTFye2vxGi0Lfw2VYCci9SKwWK0bBAKI4s7QuI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Aitom3VRmZ+Z5+JLzYDslBFis1PHqGW9SKuYB3e59vwR7mr+WDkr1yh9tzYVAKQJI yigT+aR1y4xYvoZlAixkJg9ASLrMRXQw1dIreUP0COgRd/J/S9V2VJmFpYjKPQ/rA2 6fUC4IbjOmCU2BpkKRsboRntazSyXta8UG6Z+L/U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731950AbgI2MJv (ORCPT ); Tue, 29 Sep 2020 08:09:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:50012 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730206AbgI2Lhf (ORCPT ); Tue, 29 Sep 2020 07:37:35 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0121B21D41; Tue, 29 Sep 2020 11:23:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601378602; bh=LJr5lMTFye2vxGi0Lfw2VYCci9SKwWK0bBAKI4s7QuI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PROG3aVo+i8DOSP/0Q0RCy/eOUc0ncmo5NDGQLhAgGa43gl7nJB/G3R/FgjQuQinQ SVCEEu19Bsai6KYxFSe258UwOHev/RKIA8lcULkKhbz7env4P3sQ+NFviefEUqfLX/ Xvo++Hpd7C8eeBrFT6d+7cGfdhO1ArlmNvDrPmH8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mohan Kumar , Viswanath L , Takashi Iwai , Sasha Levin Subject: [PATCH 4.19 071/245] ALSA: hda: Clear RIRB status before reading WP Date: Tue, 29 Sep 2020 12:58:42 +0200 Message-Id: <20200929105950.450875799@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105946.978650816@linuxfoundation.org> References: <20200929105946.978650816@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mohan Kumar [ Upstream commit 6d011d5057ff88ee556c000ac6fe0be23bdfcd72 ] RIRB interrupt status getting cleared after the write pointer is read causes a race condition, where last response(s) into RIRB may remain unserviced by IRQ, eventually causing azx_rirb_get_response to fall back to polling mode. Clearing the RIRB interrupt status ahead of write pointer access ensures that this condition is avoided. Signed-off-by: Mohan Kumar Signed-off-by: Viswanath L Link: https://lore.kernel.org/r/1580983853-351-1-git-send-email-viswanathl@nvidia.com Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/pci/hda/hda_controller.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c index fa261b27d8588..8198d2e53b7df 100644 --- a/sound/pci/hda/hda_controller.c +++ b/sound/pci/hda/hda_controller.c @@ -1169,16 +1169,23 @@ irqreturn_t azx_interrupt(int irq, void *dev_id) if (snd_hdac_bus_handle_stream_irq(bus, status, stream_update)) active = true; - /* clear rirb int */ status = azx_readb(chip, RIRBSTS); if (status & RIRB_INT_MASK) { + /* + * Clearing the interrupt status here ensures that no + * interrupt gets masked after the RIRB wp is read in + * snd_hdac_bus_update_rirb. This avoids a possible + * race condition where codec response in RIRB may + * remain unserviced by IRQ, eventually falling back + * to polling mode in azx_rirb_get_response. + */ + azx_writeb(chip, RIRBSTS, RIRB_INT_MASK); active = true; if (status & RIRB_INT_RESPONSE) { if (chip->driver_caps & AZX_DCAPS_CTX_WORKAROUND) udelay(80); snd_hdac_bus_update_rirb(bus); } - azx_writeb(chip, RIRBSTS, RIRB_INT_MASK); } } while (active && ++repeat < 10); -- 2.25.1