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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 A5DACC433FF for ; Fri, 9 Aug 2019 10:01:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77AA72166E for ; Fri, 9 Aug 2019 10:01:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="QPLLSo/c" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406284AbfHIKBC (ORCPT ); Fri, 9 Aug 2019 06:01:02 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:40320 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726152AbfHIKBC (ORCPT ); Fri, 9 Aug 2019 06:01:02 -0400 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id x79A0fRI048307; Fri, 9 Aug 2019 05:00:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1565344841; bh=j7mV9yfiX1/T+LAXN7sKBAuBWQGSmBtE1m1dH8dWDMg=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=QPLLSo/c7PIM3IuGLr4tUxL+fOeHcEbojhZeuCoDWET+gNyhZpH6nmpNZaHGQBVqj DNMViz9lSN0NsV7J62W8tS312+ItZBvVahpOkRRl20KnZxzYEJnTOHZ4Mqqr1H55pO F+wWLyu8c25UQA5TzPsQSgN4Dm2lBLMw9gis9LUQ= Received: from DFLE103.ent.ti.com (dfle103.ent.ti.com [10.64.6.24]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x79A0fBs067623 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 9 Aug 2019 05:00:41 -0500 Received: from DFLE108.ent.ti.com (10.64.6.29) by DFLE103.ent.ti.com (10.64.6.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Fri, 9 Aug 2019 05:00:41 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE108.ent.ti.com (10.64.6.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Fri, 9 Aug 2019 05:00:41 -0500 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id x79A0dKm006580; Fri, 9 Aug 2019 05:00:39 -0500 Subject: Re: [PATCH for-5.3] drm/omap: ensure we have a valid dma_mask To: Christoph Hellwig CC: , , , , "H. Nikolaus Schaller" , Tony Lindgren , Peter Ujfalusi References: <20190808101042.18809-1-hch@lst.de> <7fff8fd3-16ae-1f42-fcd6-9aa360fe36b5@ti.com> <20190809080750.GA21874@lst.de> From: Tomi Valkeinen Message-ID: Date: Fri, 9 Aug 2019 13:00:38 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190809080750.GA21874@lst.de> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/08/2019 11:07, Christoph Hellwig wrote: > On Fri, Aug 09, 2019 at 09:40:32AM +0300, Tomi Valkeinen wrote: >> We do call dma_set_coherent_mask() in omapdrm's probe() (in omap_drv.c), >> but apparently that's not enough anymore. Changing that call to >> dma_coerce_mask_and_coherent() removes the WARN. I can create a patch for >> that, or Christoph can respin this one. > > Oh, yes - that actually is the right thing to do here. If you already > have it please just send it out. > >> >> I am not too familiar with the dma mask handling, so maybe someone can >> educate: >> >> dma_coerce_mask_and_coherent() overwrites dev->dma_mask. Isn't that a bad >> thing? What if the platform has set dev->dma_mask, and the driver >> overwrites it with its value? Or who is supposed to set dev->dma_mask? > > ->dma_mask is a complete mess. It is a pointer when it really should > just be a u64, and that means every driver layer has to allocate space > for it. We don't really do that for platform_devices, as that breaks > horribly assumptions in the usb code. That is why > dma_coerce_mask_and_coherent exists as a nasty workaround that sets > the dma_mask to the coherent_dma_mask for devices that don't have > space for ->dma_mask allocated, which works as long as the device > doesn't have differnet addressing requirements for both. > > I'm actually working to fix that mess up at the moment, but it is going > to take a few cycles until everything falls into place. Alright, thanks for the clarification! Here's my version. >From c258309e36fc86076db155aead03a3900b96c3d4 Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Fri, 9 Aug 2019 09:54:49 +0300 Subject: [PATCH] drm/omap: ensure we have a valid dma_mask The omapdrm driver uses dma_set_coherent_mask(), but that's not enough anymore when LPAE is enabled. >From Christoph Hellwig : The traditional arm DMA code ignores, but the generic dma-direct/swiotlb has stricter checks and thus fails mappings without a DMA mask. As we use swiotlb for arm with LPAE now, omapdrm needs to catch up and actually set a DMA mask. Change the dma_set_coherent_mask() call to dma_coerce_mask_and_coherent() so that the dev->dma_mask is also set. Fixes: ad3c7b18c5b3 ("arm: use swiotlb for bounce buffering on LPAE configs") Reported-by: "H. Nikolaus Schaller" Signed-off-by: Tomi Valkeinen diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c index 288c59dae56a..1bad0a2cc5c6 100644 --- a/drivers/gpu/drm/omapdrm/omap_drv.c +++ b/drivers/gpu/drm/omapdrm/omap_drv.c @@ -669,7 +669,7 @@ static int pdev_probe(struct platform_device *pdev) if (omapdss_is_initialized() == false) return -EPROBE_DEFER; - ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32)); + ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); if (ret) { dev_err(&pdev->dev, "Failed to set the DMA mask\n"); return ret; -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. 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