From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753625AbbJTJqq (ORCPT ); Tue, 20 Oct 2015 05:46:46 -0400 Received: from smtp-out-200.synserver.de ([212.40.185.200]:1132 "EHLO smtp-out-188.synserver.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932066AbbJTJqo (ORCPT ); Tue, 20 Oct 2015 05:46:44 -0400 X-SynServer-TrustedSrc: 1 X-SynServer-AuthUser: lars@metafoo.de X-SynServer-PPID: 2410 From: Lars-Peter Clausen To: Vinod Koul , Takashi Iwai Cc: Dan Williams , Russell King , Laurent Pinchart , Kuninori Morimoto , Qiao Zhou , Shengjiu Wang , Matt Campbell , Jonah Petri , dmaengine@vger.kernel.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, Lars-Peter Clausen Subject: [PATCH 2/4] dmaengine: virt-dma: Add synchronization helper function Date: Tue, 20 Oct 2015 11:46:29 +0200 Message-Id: <1445334391-12272-3-git-send-email-lars@metafoo.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1445334391-12272-1-git-send-email-lars@metafoo.de> References: <1445334391-12272-1-git-send-email-lars@metafoo.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a synchronize helper function for the virt-dma library. The function makes sure that any scheduled descriptor complete callbacks have finished running before the function returns. This needs to be called by drivers using virt-dma in their device_synchronize() callback. Depending on the driver additional operations might be necessary in addition to calling vchan_synchronize() to ensure proper synchronization. Signed-off-by: Lars-Peter Clausen --- drivers/dma/virt-dma.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/dma/virt-dma.h b/drivers/dma/virt-dma.h index 181b9526..e93de76 100644 --- a/drivers/dma/virt-dma.h +++ b/drivers/dma/virt-dma.h @@ -151,4 +151,17 @@ static inline void vchan_free_chan_resources(struct virt_dma_chan *vc) vchan_dma_desc_free_list(vc, &head); } +/** + * vchan_synchronize() - synchronize callback execution to the current context + * @vc: virtual channel to synchronize + * + * Makes sure that all scheduled or active callbacks have finished running. For + * proper operation the caller has to ensure that no new callbacks are scheduled + * after the invocation of this function started. + */ +static inline void vchan_synchronize(struct virt_dma_chan *vc) +{ + tasklet_kill(&vc->task); +} + #endif -- 2.1.4