Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755341AbcCaIG2 (ORCPT ); Thu, 31 Mar 2016 04:06:28 -0400 Received: from mga01.intel.com ([192.55.52.88]:31402 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751504AbcCaIGU (ORCPT ); Thu, 31 Mar 2016 04:06:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,421,1455004800"; d="asc'?scan'208";a="922411233" From: Felipe Balbi To: "Thang Q. Nguyen" Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm@lists.infradead.org, Phong Vo , Loc Ho , patches Subject: Re: [PATCH v3 1/2] usb:dwc3: Enable support for 64-bit system In-Reply-To: References: <1457594332-7490-1-git-send-email-tqnguyen@apm.com> <1457594332-7490-2-git-send-email-tqnguyen@apm.com> <87pouci03i.fsf@intel.com> User-Agent: Notmuch/0.21+96~g9bbc54b (http://notmuchmail.org) Emacs/25.0.90.3 (x86_64-pc-linux-gnu) Date: Thu, 31 Mar 2016 11:04:13 +0300 Message-ID: <87mvpfgjk2.fsf@intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4176 Lines: 135 --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi, (please don't top-post) "Thang Q. Nguyen" writes: > Hi Balbi, > If CONFIG_DMA_CMA=3Dy, dma mask is set properly. The issue just happen > when CONFIG_DMA_CMA is not set. In this case, dma mask is not set and > we need this code to check if dma mask should be manually set to 32 or > 64. Can you point me to the code which has this conditional ? Why would DMA_CMA=3Dn mean that dma_mask isn't initialized ? According to DMA_CMA's help text (see below) that's supposed to allow drivers to *allocate* large contiguous buffers, but that's not the case here. config DMA_CMA bool "DMA Contiguous Memory Allocator" depends on HAVE_DMA_CONTIGUOUS && CMA help This enables the Contiguous Memory Allocator which allows drivers to allocate big physically-contiguous blocks of memory for use with hardware components that do not support I/O map nor scatter-gather. You can disable CMA by specifying "cma=3D0" on the kernel's command line. For more information see . If unsure, say "n". > > ---- > Thang > > On Wed, Mar 30, 2016 at 8:09 PM, Felipe Balbi > wrote: >> >> Hi, >> >> "Thang Q. Nguyen" writes: >>> From: "Thang Q. Nguyen" >>> >>> Add 64-bit DMA operation support to the USB DWC3 driver. >>> First attempt to set the coherent DMA mask for 64-bit DMA. >>> If that failed, attempt again with 32-bit DMA. >>> >>> Changes from v2: >>> - None. >>> >>> Changes from v1: >>> - Remove WARN_ON if dma_mask is NULL >> >> these changes lines should be between the tearline (---) and diffstat >> below. >> >>> Signed-off-by: Thang Q. Nguyen >>> --- >>> drivers/usb/dwc3/core.c | 15 +++++++++++++++ >>> 1 file changed, 15 insertions(+) >>> >>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c >>> index de5e01f..2479c24 100644 >>> --- a/drivers/usb/dwc3/core.c >>> +++ b/drivers/usb/dwc3/core.c >>> @@ -831,6 +831,21 @@ static int dwc3_probe(struct platform_device *pdev) >>> dwc->mem =3D mem; >>> dwc->dev =3D dev; >>> >>> + /* Try to set 64-bit DMA first */ >>> + if (!pdev->dev.dma_mask) >>> + /* Platform did not initialize dma_mask */ >>> + ret =3D dma_coerce_mask_and_coherent(&pdev->dev, >>> + DMA_BIT_MASK(64)); >>> + else >>> + ret =3D dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MAS= K(64)); >>> + >>> + /* If seting 64-bit DMA mask fails, fall back to 32-bit DMA mask = */ >>> + if (ret) { >>> + ret =3D dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MAS= K(32)); >>> + if (ret) >>> + return ret; >>> + } >> >> Also, why is it so that you need this now ? glue layers are copying dma >> mask from parent device and that should be set properly. This really >> shouldn't be necessary in dwc3-core; it would mean that glue layer >> didn't set this device up properly. >> >> -- >> balbi > > > > --=20 > > Thang Q. Nguyen | Staff SW Eng. > > C: +849.7684.7606 | O: +848.3770.0640 > > F: +848.3770.0641 | tqnguyen@apm.com =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJW/Nn9AAoJEIaOsuA1yqRE3t8P/0Ftsfei7GZ9W1ba8hEOq5L2 oQ8FYIcsqoxtxgK8AXFpxDAJtAVek8GM65+c9jO1dKcRcudM19tc7IPYo2qo8mOM 9c+rpdfCgwcC/gSBX4jLgUHnqCBlV2Cty+rIZDQDLZ1mk6D8XArH9qvKleigOfuV Thl2EvDkfd040VjR0wPv89X9XaUcaRBN6r2kPgbgPs7KEyuEe8jHoannMIGIYvKD NcUIMAF86bVFCGvV04OOi7eI6smDyNakn5JhKwTbt/GW35xpl1mI+qmSL/FxyKQ3 wenv+PsdJ6GBIhANWpyUhy0ykjnbp6WLtc2kbQWxueI/taMBSt9YlZQOmCw1iGnx fZ1+aiUosfacmrfrP9JgJC83sdeVv0ZU9APcFbey/eqQOSkxSaNjoL2IpJsOzpyk yi08uGkJ39iiN4AqhueJr1clzTn9pwufwx7y/4a07mEuKd+nVfIIL45eCjr7eUdU +uAqngrGolaq4S8KjXAsaLuFFYCl7j+zlYYeVO9MuTbR7dsGddF+f0i4cIMLUuY0 4slAwyiSKsupv4PPBYTGu0CRJhF1ahqVE4Ok2rI/dQDBy4zlS8GyaMcgN5I9+DOr +VhzscLUBvY2p2iy+q0Wkpk6Udt3ALW9zb4GEDysLBC/OiZtSR3mK0r3mwy1W7Lk WgKwhiRvjzKqwICbrtoV =fMK3 -----END PGP SIGNATURE----- --=-=-=--