From patchwork Wed Aug 28 13:32:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabrizio Castro X-Patchwork-Id: 11119059 X-Patchwork-Delegate: iwamatsu@nigauri.org Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 07EB314F7 for ; Wed, 28 Aug 2019 13:34:57 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E44142339E for ; Wed, 28 Aug 2019 13:34:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E44142339E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bp.renesas.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=cip-dev-bounces@lists.cip-project.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 69A452FC1; Wed, 28 Aug 2019 13:33:32 +0000 (UTC) X-Original-To: cip-dev@lists.cip-project.org Delivered-To: cip-dev@mail.linuxfoundation.org Received: from smtp2.linuxfoundation.org (smtp2.linux-foundation.org [172.17.192.36]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 3AC1B2F65 for ; Wed, 28 Aug 2019 13:33:20 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from relmlie6.idc.renesas.com (relmlor2.renesas.com [210.160.252.172]) by smtp2.linuxfoundation.org (Postfix) with ESMTP id AC4061DE57 for ; Wed, 28 Aug 2019 13:33:19 +0000 (UTC) X-IronPort-AV: E=Sophos;i="5.64,441,1559487600"; d="scan'208";a="24936311" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie6.idc.renesas.com with ESMTP; 28 Aug 2019 22:33:19 +0900 Received: from fabrizio-dev.ree.adwin.renesas.com (unknown [10.226.36.196]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 696AB425E32D; Wed, 28 Aug 2019 22:33:18 +0900 (JST) From: Fabrizio Castro To: cip-dev@lists.cip-project.org Date: Wed, 28 Aug 2019 14:32:09 +0100 Message-Id: <1566999164-27898-23-git-send-email-fabrizio.castro@bp.renesas.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1566999164-27898-1-git-send-email-fabrizio.castro@bp.renesas.com> References: <1566999164-27898-1-git-send-email-fabrizio.castro@bp.renesas.com> X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp2.linux-foundation.org Cc: Biju Das Subject: [cip-dev] [PATCH 4.19.y-cip v2 22/57] serial: sh-sci: Fix fallback to PIO in sci_dma_rx_complete() X-BeenThere: cip-dev@lists.cip-project.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: cip-dev-bounces@lists.cip-project.org Errors-To: cip-dev-bounces@lists.cip-project.org From: Geert Uytterhoeven commit 26f073993665683f1debf4d66d8bc274ac6df771 upstream. When submitting a DMA request fails in sci_dma_rx_complete(), the driver tries to fall back to PIO, but that does not work: no more data will be received, or the kernel will even crash. Fix this similar as in (but not identical to) sci_submit_rx(): - On SCIF, PIO cannot take over if any DMA transactions are pending, hence they must be terminated first. - All active cookies must be invalidated, else rx_timer_fn() may trigger a NULL pointer dereference. - Restarting the port is not needed, as it is already running, but serial port interrupts must be directed back from the DMA engine to the CPU. Signed-off-by: Geert Uytterhoeven Reviewed-by: Simon Horman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Fabrizio Castro --- drivers/tty/serial/sh-sci.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index d5bd3f7..29dce54 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1327,8 +1327,9 @@ static void sci_dma_rx_complete(void *arg) dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n"); /* Switch to PIO */ spin_lock_irqsave(&port->lock, flags); - s->chan_rx = NULL; - sci_start_rx(port); + dmaengine_terminate_async(chan); + sci_dma_rx_chan_invalidate(s); + sci_dma_rx_reenable_irq(s); spin_unlock_irqrestore(&port->lock, flags); }