From patchwork Mon Nov 9 15:40:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 323382 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 61FA6C4741F for ; Mon, 9 Nov 2020 15:40:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F2FF206C0 for ; Mon, 9 Nov 2020 15:40:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727303AbgKIPkR (ORCPT ); Mon, 9 Nov 2020 10:40:17 -0500 Received: from muru.com ([72.249.23.125]:47548 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726410AbgKIPkR (ORCPT ); Mon, 9 Nov 2020 10:40:17 -0500 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 80B8B80CD; Mon, 9 Nov 2020 15:40:22 +0000 (UTC) From: Tony Lindgren To: linux-omap@vger.kernel.org Cc: Vinod Koul , dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Peter Ujfalusi Subject: [PATCH] dmaengine: ti: omap-dma: Block PM if SDMA is busy to fix audio Date: Mon, 9 Nov 2020 17:40:13 +0200 Message-Id: <20201109154013.11950-1-tony@atomide.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org We now use cpu_pm for saving and restoring device context for deeper SoC idle states. But for omap3, we must also block idle if SDMA is busy. If we don't block idle when SDMA is busy, we eventually end up saving and restoring SDMA register state on PER domain idle while SDMA is active and that causes at least audio playback to fail. Fixes: 4c74ecf79227 ("dmaengine: ti: omap-dma: Add device tree match data and use it for cpu_pm") Reported-by: Peter Ujfalusi Signed-off-by: Tony Lindgren --- drivers/dma/ti/omap-dma.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c --- a/drivers/dma/ti/omap-dma.c +++ b/drivers/dma/ti/omap-dma.c @@ -1522,29 +1522,38 @@ static void omap_dma_free(struct omap_dmadev *od) } } +/* Currently used by omap2 & 3 to block deeper SoC idle states */ +static bool omap_dma_busy(struct omap_dmadev *od) +{ + struct omap_chan *c; + int lch = -1; + + while (1) { + lch = find_next_bit(od->lch_bitmap, od->lch_count, lch + 1); + if (lch >= od->lch_count) + break; + c = od->lch_map[lch]; + if (!c) + continue; + if (omap_dma_chan_read(c, CCR) & CCR_ENABLE) + return true; + } + + return false; +} + /* Currently only used for omap2. For omap1, also a check for lcd_dma is needed */ static int omap_dma_busy_notifier(struct notifier_block *nb, unsigned long cmd, void *v) { struct omap_dmadev *od; - struct omap_chan *c; - int lch = -1; od = container_of(nb, struct omap_dmadev, nb); switch (cmd) { case CPU_CLUSTER_PM_ENTER: - while (1) { - lch = find_next_bit(od->lch_bitmap, od->lch_count, - lch + 1); - if (lch >= od->lch_count) - break; - c = od->lch_map[lch]; - if (!c) - continue; - if (omap_dma_chan_read(c, CCR) & CCR_ENABLE) - return NOTIFY_BAD; - } + if (omap_dma_busy(od)) + return NOTIFY_BAD; break; case CPU_CLUSTER_PM_ENTER_FAILED: case CPU_CLUSTER_PM_EXIT: @@ -1595,6 +1604,8 @@ static int omap_dma_context_notifier(struct notifier_block *nb, switch (cmd) { case CPU_CLUSTER_PM_ENTER: + if (omap_dma_busy(od)) + return NOTIFY_BAD; omap_dma_context_save(od); break; case CPU_CLUSTER_PM_ENTER_FAILED: