From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752701AbcELKqZ (ORCPT ); Thu, 12 May 2016 06:46:25 -0400 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:41071 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751816AbcELKqY (ORCPT ); Thu, 12 May 2016 06:46:24 -0400 Message-ID: <1463049975.3070.29.camel@pengutronix.de> Subject: Re: [PATCH] drm: mediatek: remove IOMMU_DMA select From: Philipp Zabel To: Arnd Bergmann Cc: airlied@redhat.com, David Airlie , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Matthias Brugger , Bibby Hsieh , YT Shen , Mao Huang , CK Hu , linux-mediatek@lists.infradead.org Date: Thu, 12 May 2016 12:46:15 +0200 In-Reply-To: <1462997501-982363-1-git-send-email-arnd@arndb.de> References: <1462982509-342936-1-git-send-email-arnd@arndb.de> <1462997501-982363-1-git-send-email-arnd@arndb.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.9-1+b1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:96de:80ff:fec2:9969 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Mittwoch, den 11.05.2016, 22:11 +0200 schrieb Arnd Bergmann: > We get a harmless build warning when trying to use the mediatek > DRM driver with IOMMU support disabled: > > warning: (DRM_MEDIATEK) selects IOMMU_DMA which has unmet direct dependencies (IOMMU_SUPPORT) > > However, the IOMMU_DMA symbol is not meant to be used by drivers > at all, and this driver doesn't seem to have a strict dependency > on it other than using the mediatek IOMMU driver that does. > > Since we also want to be able to do compile tests with the > driver on other platforms, the IOMMU_DMA symbol should not > be selected here. > > Signed-off-by: Arnd Bergmann > --- > If someone has a better explanation about why the 'select' is here, > let me know, it certainly seems out of place. No, it just has been there since the initial RFC and nobody noticed. > drivers/gpu/drm/mediatek/Kconfig | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/mediatek/Kconfig b/drivers/gpu/drm/mediatek/Kconfig > index 0c06a69d7f04..545973f6b743 100644 > --- a/drivers/gpu/drm/mediatek/Kconfig > +++ b/drivers/gpu/drm/mediatek/Kconfig > @@ -7,7 +7,6 @@ config DRM_MEDIATEK > select DRM_KMS_HELPER > select DRM_MIPI_DSI > select DRM_PANEL > - select IOMMU_DMA > select MEMORY > select MTK_SMI > help Acked-by: Philipp Zabel I tried make ARCH=arm64 allnoconfig and then set CONFIG_MODULES=y CONFIG_ARCH_MEDIATEK=y CONFIG_DRM=m CONFIG_DRM_MEDIATEK=m And it builds fine with IOMMU_DMA/MTK_IOMMU disabled. thanks Philipp