From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Fri, 03 May 2013 13:28:38 +0200 Subject: [PATCH 9/9] ARM: ux500: always select ABX500_CORE In-Reply-To: References: <1367528578-518090-1-git-send-email-arnd@arndb.de> <1367528578-518090-10-git-send-email-arnd@arndb.de> Message-ID: <15723843.9mConxltov@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 03 May 2013 10:14:28 Linus Walleij wrote: > > I do not necessarily agree with this commit message. > > The only mess I see is that this very patch is missing... > > If we look at this: > > config UX500_SOC_DB8500 > bool > select CPU_FREQ_TABLE if CPU_FREQ > select MFD_DB8500_PRCMU > select PINCTRL_DB8500 > select PINCTRL_DB8540 > select PINCTRL_AB8500 > select PINCTRL_AB8505 > select PINCTRL_AB9540 > select PINCTRL_AB8540 > select REGULATOR > select REGULATOR_DB8500_PRCMU > > The PRCMU, the PINCTRL drivers, and the PRCMU regulators > are necessary to boot the system correctly, by which I mean > necessary so as not to cause potential damage to the hardware. > > The PRCMU is a system controller without which the system > cannot really be brought up, and the ABx500's are the PMICs > which are developed in pair with the SoC and they are in practice > Siamese twins, there is no chance you can build a Ux500 system > without both of them. It just won't even start. There are deep > dependencies between the PRCMU and the ABx500, as the > PRCMU firmware will talk directly to the ABx500 without the > kernel intervening. I.e. the whole set of hardware has to be > there. > > While I understand that from a compile-time point of view it does > not seem nice, and all things would be separate units that you > plug in, from a run-time and system architecture point of view it > makes a lot of sense to select these. Worlds collide... > > Apart from that: > Acked-by: Linus Walleij If they are completely essential, we should not have an entry like config AB8500_CORE bool "ST-Ericsson AB8500 Mixed Signal Power Management chip" depends on GENERIC_HARDIRQS && ABX500_CORE && MFD_DB8500_PRCMU select POWER_SUPPLY select MFD_CORE select IRQ_DOMAIN help Select this option to enable access to AB8500 power management chip. This connects to U8500 either on the SSP/SPI bus (deprecated since hardware version v1.0) or the I2C bus via PRCMU. It also adds the irq_chip parts for handling the Mixed Signal chip events. This chip embeds various other multimedia funtionalities as well. (and more of the same) in drivers/mfd/Kconfig. The rule is that you either make a Kconfig option user-selectable or make it always selected by another option. My preference would be to make it user-selectable and enable it only in the defconfig, but if that can damage the hardware, we should not actually provide a named option. Arnd