From patchwork Tue Oct 25 09:02:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tudor Ambarus X-Patchwork-Id: 13018776 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C399C38A2D for ; Tue, 25 Oct 2022 09:03:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231953AbiJYJD3 (ORCPT ); Tue, 25 Oct 2022 05:03:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231888AbiJYJD0 (ORCPT ); Tue, 25 Oct 2022 05:03:26 -0400 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.153.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2D05159A1F; Tue, 25 Oct 2022 02:03:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1666688605; x=1698224605; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=l7OewSpbHJXGmYf7pMLsslFC7RsyklewLjVzhb94scc=; b=DilI6tNfwHYVhBs6vw5VKo5veGYy+6HdRKgSEz8HIdYIro2zmmxrZXeu jJniAliOxF4QqDyZDOrdyyfeKUjJt4OtSeYKWwlC7pf5vYETlDFbqYsMW ZT/NfRqsEIQV4/5dT/kCmCpRVzno/Au0d6UxzOsUMK9vG/I9i2J4Nap9j xIjLry2LrOnXv7wubTWrZoi7OIbUMlaKjdxUUKXw7bW+y9orCJeEr70RR n+3eXRcx4HcHBkcVQ7MtPN/G/JOzGAHPkjkvSR9pjq53DQJ6DLX3YDNyx HuE8a+RGGxoABvDtQXpZ/cvVtT59E+olYfGoTJRp7IXN7gEH3FVHrbpTy A==; X-IronPort-AV: E=Sophos;i="5.95,211,1661842800"; d="scan'208";a="186273050" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa3.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 25 Oct 2022 02:03:25 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.85.151) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.12; Tue, 25 Oct 2022 02:03:24 -0700 Received: from ROB-ULT-M18064N.mchp-main.com (10.10.115.15) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server id 15.1.2507.12 via Frontend Transport; Tue, 25 Oct 2022 02:03:21 -0700 From: Tudor Ambarus To: , , CC: , , , , , , , "Tudor Ambarus" , Subject: [PATCH v2 04/32] dmaengine: at_hdmac: Fix premature completion of desc in issue_pending Date: Tue, 25 Oct 2022 12:02:38 +0300 Message-ID: <20221025090306.297886-5-tudor.ambarus@microchip.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221025090306.297886-1-tudor.ambarus@microchip.com> References: <20221025090306.297886-1-tudor.ambarus@microchip.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Multiple calls to atc_issue_pending() could result in a premature completion of a descriptor from the atchan->active list, as the method always completed the first active descriptor from the list. Instead, issue_pending() should just take the first transaction descriptor from the pending queue, move it to active_list and start the transfer. Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller") Reported-by: Peter Rosin Signed-off-by: Tudor Ambarus Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/ --- drivers/dma/at_hdmac.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index e9d0c3632868..cb5522417db6 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -1527,16 +1527,26 @@ atc_tx_status(struct dma_chan *chan, } /** - * atc_issue_pending - try to finish work + * atc_issue_pending - takes the first transaction descriptor in the pending + * queue and starts the transfer. * @chan: target DMA channel */ static void atc_issue_pending(struct dma_chan *chan) { - struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_desc *desc; + unsigned long flags; dev_vdbg(chan2dev(chan), "issue_pending\n"); - atc_advance_work(atchan); + spin_lock_irqsave(&atchan->lock, flags); + if (atc_chan_is_enabled(atchan) || list_empty(&atchan->queue)) + return spin_unlock_irqrestore(&atchan->lock, flags); + + desc = atc_first_queued(atchan); + list_move_tail(&desc->desc_node, &atchan->active_list); + atc_dostart(atchan, desc); + spin_unlock_irqrestore(&atchan->lock, flags); } /**