From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753051AbdLLX7p (ORCPT ); Tue, 12 Dec 2017 18:59:45 -0500 Received: from mail-pf0-f196.google.com ([209.85.192.196]:36419 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752886AbdLLX7H (ORCPT ); Tue, 12 Dec 2017 18:59:07 -0500 X-Google-Smtp-Source: ACJfBotAb0sxqDsqPrRkaQ7/jsBscrgDayN2SQun4lRU9RW4MBGtswyVuQCuBVyy3dklt0t2i8WeKg== From: Bjorn Andersson To: Ohad Ben-Cohen , Bjorn Andersson Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Chris Lew , Jeremy McNicoll , Will Newton Subject: [PATCH 5/5] rpmsg: smd: Don't hold the tx lock during wait Date: Tue, 12 Dec 2017 15:58:57 -0800 Message-Id: <20171212235857.10432-6-bjorn.andersson@linaro.org> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171212235857.10432-1-bjorn.andersson@linaro.org> References: <20171212235857.10432-1-bjorn.andersson@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Holding the tx lock while waiting for tx-drain events from the remote side blocks try_send requests from failing quickly, so temporarily drop the tx lock while waiting. While this allows try_send to fail quickly it also could allow a subsequent send to succeed putting a smaller packet in the FIFO while we're waiting for room for our large packet. But as this lock is per channel we expect that clients with ordering concerns implements their own ordering mechanism. Signed-off-by: Bjorn Andersson --- drivers/rpmsg/qcom_smd.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/rpmsg/qcom_smd.c b/drivers/rpmsg/qcom_smd.c index ed167ab52a68..10870189c0c8 100644 --- a/drivers/rpmsg/qcom_smd.c +++ b/drivers/rpmsg/qcom_smd.c @@ -752,12 +752,19 @@ static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data, SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0); + /* Wait without holding the tx_lock */ + mutex_unlock(&channel->tx_lock); + ret = wait_event_interruptible(channel->fblockread_event, qcom_smd_get_tx_avail(channel) >= tlen || channel->state != SMD_CHANNEL_OPENED); if (ret) goto out; + ret = mutex_lock_interruptible(&channel->tx_lock); + if (ret) + goto out; + SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1); } -- 2.15.0