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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 7B0B1C7618B for ; Thu, 25 Jul 2019 13:29:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48E2022C7B for ; Thu, 25 Jul 2019 13:29:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564061363; bh=jl8uMjgsLb0dxJ6gayUlxRXBHnr28czfXaxtk3fYBIc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=y1NB06KMevS2gWeeQgB8kDDQ750/ExmNW7sMX6BB7K3Nz6fIGMOrCI5AI9am9+KfK 36aVGOxX6NEDjAiFj8NzmtTRCcx1GEl0F8JmBHwkYxCoYRbXDdI3SqW7GwHe4eKYSU 96o/6RHlR1RG+l9BGhMnRcNADintSD3d1gkJdtY8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727658AbfGYN3X (ORCPT ); Thu, 25 Jul 2019 09:29:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:44006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726949AbfGYN3W (ORCPT ); Thu, 25 Jul 2019 09:29:22 -0400 Received: from localhost (unknown [106.200.241.217]) (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 1C2712190F; Thu, 25 Jul 2019 13:29:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564061361; bh=jl8uMjgsLb0dxJ6gayUlxRXBHnr28czfXaxtk3fYBIc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=p/v9siQZKZQYp+JHwgRMPxxJz9BRFGxp87Koei1lbF8P2wLiOQmvpJ1yYn2HhiI3M oaw5G9ciDLtOC1zOgo3l4b+Kr3GFPcH9b71R3llwsng4qW8B0to7FlO9xzXRp2O4R+ LYuPS8yRPj18gwKIl4EyJNZ3JySk1pf8dL+evhMw= Date: Thu, 25 Jul 2019 18:58:09 +0530 From: Vinod Koul To: Paul Cercueil Cc: Paul Burton , od@zcrc.me, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] dmaengine: dma-jz4780: Break descriptor chains on JZ4740 Message-ID: <20190725132809.GW12733@vkoul-mobl.Dlink> References: <20190714215504.10877-1-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190714215504.10877-1-paul@crapouillou.net> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 14-07-19, 17:55, Paul Cercueil wrote: > The current driver works perfectly fine on every generation of the > JZ47xx SoCs, except on the JZ4740. > > There, when hardware descriptors are chained together (with the LINK > bit set), the next descriptor isn't automatically fetched as it should - > instead, an interrupt is raised, even if the TIE bit (Transfer Interrupt > Enable) bit is cleared. When it happens, the DMA transfer seems to be > stopped (it doesn't chain), and it's uncertain how many bytes have > actually been transferred. > > Until somebody smarter than me can figure out how to make chained > descriptors work on the JZ4740, we now disable chained descriptors on > that particular SoC. Applied, thanks -- ~Vinod