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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E295C433EF for ; Tue, 9 Nov 2021 01:27:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1662C60FC2 for ; Tue, 9 Nov 2021 01:27:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243307AbhKIBan (ORCPT ); Mon, 8 Nov 2021 20:30:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:53836 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243837AbhKIBXs (ORCPT ); Mon, 8 Nov 2021 20:23:48 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6F3A261A70; Tue, 9 Nov 2021 01:09:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636420166; bh=GfOpFnXAiHmX3z8uL6XtcSjQjINziKqF1YSeaM9QeMU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F+fSz7zTNnrT7RwiphBOHnZziiFglJxSJ9L+CP5L0Ecb1Heabb0DvY+Z91EPcKr9i zzFDzILAO5HmofAks9md2I9X+CaKZ9k57Rtkv/+9mge6NaNhReGnJfNNIqhhDXJoJF m7htJbfIz+ISTR+ltJx5KZmnUcioL+QU12RQwexM1U0c9BykI3RFbukxOOp/tTmbGA Xh/Ab2MSFJ1bartdCJQ27E7vSB6+H+q91FraHJn86y77tbPSPrQu+CsGc+9oQTQJ/G bec9fD2EI0n+ADoL9fP0YR6TI9mGLmHPydmtMimwj9gGp99tJoq9M2jQEIYnq0AaGy DssYYxOUZVVqw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Aleksander Jan Bajkowski , "David S . Miller" , Sasha Levin , john@phrozen.org, tsbogend@alpha.franken.de, hauke@hauke-m.de, maz@kernel.org, linux-mips@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 04/30] MIPS: lantiq: dma: add small delay after reset Date: Mon, 8 Nov 2021 20:08:52 -0500 Message-Id: <20211109010918.1192063-4-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211109010918.1192063-1-sashal@kernel.org> References: <20211109010918.1192063-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Aleksander Jan Bajkowski [ Upstream commit c12aa581f6d5e80c3c3675ab26a52c2b3b62f76e ] Reading the DMA registers immediately after the reset causes Data Bus Error. Adding a small delay fixes this issue. Signed-off-by: Aleksander Jan Bajkowski Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- arch/mips/lantiq/xway/dma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/mips/lantiq/xway/dma.c b/arch/mips/lantiq/xway/dma.c index 34a116e840d8b..932161284213c 100644 --- a/arch/mips/lantiq/xway/dma.c +++ b/arch/mips/lantiq/xway/dma.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include @@ -232,6 +233,8 @@ ltq_dma_init(struct platform_device *pdev) clk_enable(clk); ltq_dma_w32_mask(0, DMA_RESET, LTQ_DMA_CTRL); + usleep_range(1, 10); + /* disable all interrupts */ ltq_dma_w32(0, LTQ_DMA_IRNEN); -- 2.33.0