From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Weinberger Subject: Re: [PATCH 1/2] asm-generic/io.h: provide default ioremap/iounmap for !HAS_IOMEM Date: Tue, 29 Mar 2016 21:50:15 +0200 Message-ID: <56FADC77.1060703@nod.at> References: <1459275781-3863-1-git-send-email-robh@kernel.org> <3074778.3TElYrXjM1@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from a.ns.miles-group.at ([95.130.255.143]:11949 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754056AbcC2TuU (ORCPT ); Tue, 29 Mar 2016 15:50:20 -0400 In-Reply-To: <3074778.3TElYrXjM1@wuerfel> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Arnd Bergmann , Rob Herring Cc: Lee Jones , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net Am 29.03.2016 um 21:37 schrieb Arnd Bergmann: > On Tuesday 29 March 2016 13:23:00 Rob Herring wrote: >> Drivers shouldn't have to care about HAS_IOMEM to compile and having to >> causes a Kconfig mess: >> >> warning: (MEDIA_SUBDRV_AUTOSELECT && VIDEO_CX231XX && INV_MPU6050_I2C) selects I2C_MUX which has unmet direct dependencies (I2C && HAS_IOMEM) >> warning: (ST_IRQCHIP && STMMAC_PLATFORM && DWMAC_IPQ806X && DWMAC_LPC18XX && DWMAC_ROCKCHIP && DWMAC_SOCFPGA && DWMAC_STI && TI_CPSW && PINCTRL_ROCKCHIP && PINCTRL_DOVE && POWER_RESET_KEYSTONE && S3C2410_WATCHDOG && VIDEO_OMAP3 && VIDEO_S5P_FIMC && USB_XHCI_MTK && RTC_DRV_AT91SAM9 && LPC18XX_DMAMUX && VIDEO_OMAP4 && HWSPINLOCK_QCOM && ATMEL_ST && QCOM_GSBI && PHY_HI6220_USB) selects MFD_SYSCON which has unmet direct dependencies (HAS_IOMEM) >> >> Reuse the !MMU variants for !HAS_IOMEM as they are sufficient for our >> needs. This fixes build errors for UM allyesconfig: >> >> drivers/mfd/syscon.c:89:2: error: implicit declaration of function 'iounmap' [-Werror=implicit-function-declaration] >> iounmap(base); >> >> Reported-by: Fengguang Wu >> Cc: Arnd Bergmann >> Cc: linux-arch@vger.kernel.org >> Signed-off-by: Rob Herring > > (adding Richard and the UML list to cc) For the above error I've sent already a fix: https://lkml.org/lkml/2016/3/25/321 > I actually prototyped a patch that did the opposite: remove the readl/writel/... > definitions when HAS_IOMEM is unset. I didn't get far enough to submit it, > but see below for what I did. > > I think it makes sense to do either one or the other. > > Arnd > > diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig > index a043107..f6dc17a 100644 > --- a/drivers/char/Kconfig > +++ b/drivers/char/Kconfig > @@ -8,6 +8,7 @@ source "drivers/tty/Kconfig" > > config DEVMEM > bool "/dev/mem virtual device support" > + depends on HAS_IOMEM Hmm, this means no /dev/mem device for UML? (And some s390 variants). Not sure if this a good idea. But I like it more than having ioremap/iounmap stubs for !HAS_IOMEM. :) Thanks, //richard