From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Fri, 9 Sep 2011 10:28:14 -0700 Subject: [PATCH 2/6] arm/imx6q: add core definitions and low-level debug uart In-Reply-To: <201109081656.33404.arnd@arndb.de> References: <1315303120-24203-1-git-send-email-shawn.guo@linaro.org> <20110907142350.GU6619@n2100.arm.linux.org.uk> <201109081656.33404.arnd@arndb.de> Message-ID: <20110909172814.GI1895@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Arnd Bergmann [110908 07:23]: > On Wednesday 07 September 2011, Nicolas Pitre wrote: > > On Wed, 7 Sep 2011, Russell King - ARM Linux wrote: > > > > > On Wed, Sep 07, 2011 at 02:36:35PM +0200, Uwe Kleine-K?nig wrote: > > > > But only if the image doesn't support imx6q, right? Anyhow, I hope > > > > imx6q_map_io isn't called for pre-imx6q SoCs. Ah, and I hope we don't > > > > need to argue here as Russell doesn't like the new DEBUG_LL changes :-) > > > > > > I have no problem with the Kconfig menu approach or existing approaches > > > to DEBUG_LL. What I have an objection to is trying to stuff the > > > information for it into places which ultimately render the facility > > > useless for its intended purpose - to permit debugging the really > > > early assembly code. > > > > > > That is what it was written for: if we introduce complicated ways to > > > put behind it, we'll need to come up with a completely new debugging > > > infrastructure to debug the now buggered debugging infrastructure. > > > > For the record I now agree with Russell. > > > > In order to have early serial output that works across multiple SOCs in > > the same kernel image intended to non developers we'll have to add a > > parallel infrastructure. Keeping the DEBUG_LL code as simple as > > possible for developers is the way to go (and that might be needed to > > debug that parallel infrastructure). > > Yes, agreed. It should not be too hard to provide more CON_BOOT consoles. > For 8250, this can actually be done already using the code from > drivers/tty/serial/8250_early.c with a custom command line, but there > are better ways to do that in a generic way. Sounds good to me. Regards, Tony