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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 4F6B0CA9EC9 for ; Mon, 4 Nov 2019 22:03:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20E46205C9 for ; Mon, 4 Nov 2019 22:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572905031; bh=rEw6/0ngp8Wp6WGOhAm91Smw+MfbABi+s3SIPmYgjGY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yDzXXrTuJ2PAhWQDjHY1nvlCCw0jGN/GHKthjXcnoDwe8dDOS60/afaJhK1d7Ylwg RxqtyI1aWbxWKyOD0TPTT/CZCzNQQZAmC4jEgyWHL7vgzku4ijb7oGSCDVGOhk52YG 6be2Tcc93izOdzORwVSflv9J/0RoJozDzxrvV0JM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389123AbfKDWDt (ORCPT ); Mon, 4 Nov 2019 17:03:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:34176 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389562AbfKDWDp (ORCPT ); Mon, 4 Nov 2019 17:03:45 -0500 Received: from localhost (6.204-14-84.ripe.coltfrance.com [84.14.204.6]) (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 B8F95205C9; Mon, 4 Nov 2019 22:03:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572905024; bh=rEw6/0ngp8Wp6WGOhAm91Smw+MfbABi+s3SIPmYgjGY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1fg5Z2VeGF+kxQJMIqKov6UqG4Sf06p+bii+cPBwOVIz+oH9S5fbGr8i1k+z+re8N eH2Drdnh1EW1/oIMYGsjDZCPBrsjUHVfGW3SWw7RsLsHIVG+6CzNTfu4a90qThBMG+ SKHYhdiqY869hHRFVOnpb9pcIei6cOCB19NYqL+g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yegor Yefremov , Tony Lindgren , Vinod Koul Subject: [PATCH 4.19 132/149] dmaengine: cppi41: Fix cppi41_dma_prep_slave_sg() when idle Date: Mon, 4 Nov 2019 22:45:25 +0100 Message-Id: <20191104212146.038294606@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191104212126.090054740@linuxfoundation.org> References: <20191104212126.090054740@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tony Lindgren commit bacdcb6675e170bb2e8d3824da220e10274f42a7 upstream. Yegor Yefremov reported that musb and ftdi uart can fail for the first open of the uart unless connected using a hub. This is because the first dma call done by musb_ep_program() must wait if cppi41 is PM runtime suspended. Otherwise musb_ep_program() continues with other non-dma packets before the DMA transfer is started causing at least ftdi uarts to fail to receive data. Let's fix the issue by waking up cppi41 with PM runtime calls added to cppi41_dma_prep_slave_sg() and return NULL if still idled. This way we have musb_ep_program() continue with PIO until cppi41 is awake. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Reported-by: Yegor Yefremov Signed-off-by: Tony Lindgren Cc: stable@vger.kernel.org # v4.9+ Link: https://lore.kernel.org/r/20191023153138.23442-1-tony@atomide.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/ti/cppi41.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) --- a/drivers/dma/ti/cppi41.c +++ b/drivers/dma/ti/cppi41.c @@ -585,9 +585,22 @@ static struct dma_async_tx_descriptor *c enum dma_transfer_direction dir, unsigned long tx_flags, void *context) { struct cppi41_channel *c = to_cpp41_chan(chan); + struct dma_async_tx_descriptor *txd = NULL; + struct cppi41_dd *cdd = c->cdd; struct cppi41_desc *d; struct scatterlist *sg; unsigned int i; + int error; + + error = pm_runtime_get(cdd->ddev.dev); + if (error < 0) { + pm_runtime_put_noidle(cdd->ddev.dev); + + return NULL; + } + + if (cdd->is_suspended) + goto err_out_not_ready; d = c->desc; for_each_sg(sgl, sg, sg_len, i) { @@ -610,7 +623,13 @@ static struct dma_async_tx_descriptor *c d++; } - return &c->txd; + txd = &c->txd; + +err_out_not_ready: + pm_runtime_mark_last_busy(cdd->ddev.dev); + pm_runtime_put_autosuspend(cdd->ddev.dev); + + return txd; } static void cppi41_compute_td_desc(struct cppi41_desc *d)