From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mout.kundenserver.de ([212.227.126.130]:53301 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751383AbcCCNAW (ORCPT ); Thu, 3 Mar 2016 08:00:22 -0500 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: Geert Uytterhoeven , Krzysztof Kozlowski , Linus Walleij , Sebastian Reichel , David Brown , Alexandre Belloni , Laurent Pinchart , Lee Jones , Dan Williams , driverdevel , "linux-samsung-soc@vger.kernel.org" , Vinod Koul , Daniel Lezcano , Kishon Vijay Abraham I , Andy Gross , Linux Media Mailing List , Jason Cooper , RTCLINUX , Mauro Carvalho Chehab , Marc Zyngier , "linux-arm-msm@vger.kernel.org" , "linux-gpio@vger.kernel.org" , Giuseppe Cavallaro , Thomas Gleixner , linux-soc@vger.kernel.org, Alessandro Zummo , Greg Kroah-Hartman , Linux PM list , USB list , "linux-kernel@vger.kernel.org" , Dmitry Eremin-Solenikov , "netdev@vger.kernel.org" , dmaengine@vger.kernel.org, David Woodhouse Subject: Re: [RFC 08/15] rtc: at91sam9: Add missing MFD_SYSCON dependency on HAS_IOMEM Date: Thu, 03 Mar 2016 13:58:33 +0100 Message-ID: <4070388.ZbRf8kMntA@wuerfel> In-Reply-To: References: <1456992221-26712-1-git-send-email-k.kozlowski@samsung.com> <2233190.1BxevBAvDE@wuerfel> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: On Thursday 03 March 2016 13:27:59 Geert Uytterhoeven wrote: > On Thu, Mar 3, 2016 at 11:55 AM, Arnd Bergmann wrote: > > On Thursday 03 March 2016 17:03:34 Krzysztof Kozlowski wrote: > >> index 0da40e2e4280..5c530b6b125d 100644 > >> --- a/drivers/rtc/Kconfig > >> +++ b/drivers/rtc/Kconfig > >> @@ -1302,6 +1302,7 @@ config RTC_DRV_AT91RM9200 > >> config RTC_DRV_AT91SAM9 > >> tristate "AT91SAM9 RTT as RTC" > >> depends on ARCH_AT91 || COMPILE_TEST > >> + depends on HAS_IOMEM # For MFD_SYSCON > >> select MFD_SYSCON > >> help > >> Some AT91SAM9 SoCs provide an RTT (Real Time Timer) block which > >> > > > > This is technically correct, but the entire RTC menu is hidden > > inside of 'depends on !UML && !S390', so we won't ever get there > > on any configuration that does not use HAS_IOMEM. > > > > If we did, all other RTC drivers would also fail. > > So UML has no RTC. Should/can it use RTC_DRV_GENERIC? I think nothing should use that, even if it could ;-) Funny enough, RTC_DRV_GENERIC would probably actually work if you run UML as root and set iopl() to allow port access, but we don't really want it to mess with the host RTC. I don't know where UML gets it real time, but it doesn't actually need much other than calling clock_gettime(CLOCK_REALTIME, ...) to get the host time. Presumably it uses some variation of that. Arnd