From mboxrd@z Thu Jan 1 00:00:00 1970 From: Magnus Damm Date: Wed, 14 Oct 2015 08:09:51 +0000 Subject: Re: [PATCH] ARM: shmobile: defconfig: enable HDMI output for RCar Message-Id: List-Id: References: <1407974835-11064-1-git-send-email-khilman@linaro.org> In-Reply-To: <1407974835-11064-1-git-send-email-khilman@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org Hi Geert, On Wed, Oct 14, 2015 at 4:54 PM, Geert Uytterhoeven wrote: > Hi Magnus, > > On Wed, Oct 14, 2015 at 9:44 AM, Magnus Damm wrote: >> On Wed, Oct 14, 2015 at 4:07 PM, Geert Uytterhoeven >> wrote: >>> On Wed, Oct 14, 2015 at 3:09 AM, Laurent Pinchart >>> wrote: >>>>> Tested with a Lager board and using both I2C/IIC. Based on my testings in >>>>> Dublin with a Koelsch board, I'd be very surprised if it fails with Koelsch. >>>>> Laurent may prove me wrong ;) >>>> >>>> I've tried to reproduce the problem tonight and couldn't, even without your >>>> recent i2c-rcar patches :-/ I'll keep running tests on Koelsch with that >>>> configuration and make sure to report any issue I can find. >>> >>> The Koelsch that failed has a much newer U-Boot (b653737dfca2), which >>> only enables the MSTP clocks that are really needed, while you and I have >>> much older versions (I have b6af5fcc8dfc). >> >> With the new CPG-MSSR driver it should be possible to disable unused >> MSTP clocks in the kernel during boot without too much trouble, right? >> Of course it is not something that is needed right away, but DT >> architecture wise it seems possible to squeeze that in without having >> to update the DT binding. > > Unused clocks are already disabled by the clock framework, but that > happens at late_initcall() time, i.e. after i2c probing. Oh, right.. > Or do you mean disabling them upfront? > There are some clocks that must not be disabled. Some of them are not > documented. Disabling them upfront with sparse documentation seems fun, but also a bit like asking for trouble. =) So disabling clocks upfront may be a troublesome but good way to trigger incorrect dependencies, and unless I'm mistaken it should give the same behaviour as the updated u-boot version, right? Cheers, / magnus