From patchwork Tue Oct 22 14:55:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 11204673 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 78C961895 for ; Tue, 22 Oct 2019 14:56:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60B312084B for ; Tue, 22 Oct 2019 14:56:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731856AbfJVO4B (ORCPT ); Tue, 22 Oct 2019 10:56:01 -0400 Received: from muru.com ([72.249.23.125]:38830 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727582AbfJVO4B (ORCPT ); Tue, 22 Oct 2019 10:56:01 -0400 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 4734C80FA; Tue, 22 Oct 2019 14:56:33 +0000 (UTC) From: Tony Lindgren To: Dan Williams , Vinod Koul Cc: Alexandre Bailon , Andy Shevchenko , Bin Liu , Daniel Mack , Felipe Balbi , George Cherian , Grygorii Strashko , Johan Hovold , Peter Ujfalusi , Sekhar Nori , Sebastian Andrzej Siewior , Sergei Shtylyov , dmaengine@vger.kernel.org, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, giulio.benetti@benettiengineering.com, Sebastian Reichel , Skvortsov , Yegor Yefremov Subject: [PATCH] dmaengine: cppi41: Fix issue with musb and ftdi uart Date: Tue, 22 Oct 2019 07:55:45 -0700 Message-Id: <20191022145545.6449-1-tony@atomide.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org 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") Cc: Bin Liu Cc: giulio.benetti@benettiengineering.com Cc: Sebastian Andrzej Siewior Cc: Sebastian Reichel Cc: Skvortsov Reported-by: Yegor Yefremov Signed-off-by: Tony Lindgren --- drivers/dma/ti/cppi41.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/dma/ti/cppi41.c b/drivers/dma/ti/cppi41.c --- a/drivers/dma/ti/cppi41.c +++ b/drivers/dma/ti/cppi41.c @@ -586,9 +586,22 @@ static struct dma_async_tx_descriptor *cppi41_dma_prep_slave_sg( 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) { @@ -611,7 +624,13 @@ static struct dma_async_tx_descriptor *cppi41_dma_prep_slave_sg( 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)