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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D6A2C433FE for ; Thu, 31 Mar 2022 13:41:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236949AbiCaNnP (ORCPT ); Thu, 31 Mar 2022 09:43:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231777AbiCaNnO (ORCPT ); Thu, 31 Mar 2022 09:43:14 -0400 Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C239D214F8C; Thu, 31 Mar 2022 06:41:26 -0700 (PDT) Received: (Authenticated sender: paul.kocialkowski@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 2E6391BF20D; Thu, 31 Mar 2022 13:41:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1648734085; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=sFKjxQf/ZWijetPC66x59cvgbyQoeOo0ccVgS3BwPH8=; b=Kv4MYuUSXWAkY024BhJEbVLN3Xkj+VijVs/QKG/gKxc1YK7H/enocTPNHEmT8hip9U0LEH QLAMH8ei223plu3zy4DSm+Sh7tFkRgTcvsvZuV5tcGywYVi6l0r7hCUGehrDCDFts3w5X5 2aVwxfd+QbnP2YFNsHcmi+pz1Ws9jvRSY/YgxvV5Xxj1wOv/kE+d0z+ZgDKj6tAWdbaSlZ s1oeaA69j8+VxKykfSl2YA1vG3nuDRmyuqCAemwggos+8KdHse+pSkC9Lvp57qhjMw2LzZ Ej37Ez3K4uFLT1qNSd2jWTqVLnlJ5pidIGzpLm1WToQN0uPWKF+CsYs2hZ2/3A== From: Paul Kocialkowski To: dmaengine@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Vinod Koul , Jonathan Corbet , Thomas Petazzoni , Paul Kocialkowski Subject: [PATCH] dmaengine: Clarify cyclic transfer residue documentation Date: Thu, 31 Mar 2022 15:41:14 +0200 Message-Id: <20220331134114.703782-1-paul.kocialkowski@bootlin.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org The current documentation for the residue reported in a cyclic transfer case mentions that the reported residue should be relative to the current period only. However the definition of DMA_RESIDUE_GRANULARITY_SEGMENT specifies that the residue should be updated after each period for a cyclic transfer, which is in direct contradiction. Moreover the pcm_dmaengine common code uses the residue relative to the whole cyclic buffer size, not one period. Correct the residue-related documentation to reflect this. Signed-off-by: Paul Kocialkowski --- Documentation/driver-api/dmaengine/provider.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/driver-api/dmaengine/provider.rst b/Documentation/driver-api/dmaengine/provider.rst index 0072c9c7efd3..d3fa80e333b1 100644 --- a/Documentation/driver-api/dmaengine/provider.rst +++ b/Documentation/driver-api/dmaengine/provider.rst @@ -457,7 +457,7 @@ supported. - Should use dma_set_residue to report it - In the case of a cyclic transfer, it should only take into - account the current period. + account the total size of the cyclic buffer. - Should return DMA_OUT_OF_ORDER if the device does not support in order completion and is completing the operation out of order. -- 2.35.1