From mboxrd@z Thu Jan 1 00:00:00 1970 From: david@lechnology.com (David Lechner) Date: Tue, 3 Jan 2017 11:05:33 -0600 Subject: [v2, 1/4] ARM: davinci: da8xx-dt: Add ti-aemif lookup for clock matching In-Reply-To: <7dbaaf44-09b8-ad27-b829-afbfa50f7aa7@ti.com> References: <20160810110032.29295-2-kbeldan@baylibre.com> <33cf2e96-6551-df6a-8a30-bf2c3aeabfee@lechnology.com> <72eb6441-6463-abd8-65e6-06772b925999@ti.com> <7dbaaf44-09b8-ad27-b829-afbfa50f7aa7@ti.com> Message-ID: <40a6fd6d-9107-1620-014a-fa2f22d5cc23@lechnology.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 01/03/2017 02:58 AM, Sekhar Nori wrote: > On Monday 02 January 2017 01:34 PM, Sekhar Nori wrote: >> On Saturday 31 December 2016 06:22 AM, David Lechner wrote: >>> On 08/10/2016 06:00 AM, Karl Beldan wrote: >>>> Many davinci boards (da830 and da850 families) don't have their clocks >>>> in DT yet and won't be successful in getting an unnamed aemif clock >>>> without explicitly registering them via clk_lookups, failing the >>>> ti-aemif memory driver probe. >>>> >>>> The current aemif lookup entry resolving to the same clock: >>>> 'CLK(NULL, "aemif", &aemif_clk)' >>>> remains, as it is currently used (davinci_nand is getting a named clock >>>> "aemif"). >>>> >>>> This change will allow to switch from the mach-davinci aemif code to >>>> the ti-aemif memory driver. >>>> >>>> Signed-off-by: Karl Beldan >>>> --- >>> >>> FYI, I can't boot LEGO MINDSTORMS EV3 (AM1908) with a v4.9 mainline >>> kernel. I did a git bisect and traced it down to this patch. I'm >>> guessing that simply reverting it will break other things. >>> >>> The problem is that &aemif_clk is a node in a linked list and points to >>> itself, which creates an infinite loop when looking up the usb clocks >>> that are later in the list. >>> >>> I thought there was a patch to fix this properly from one of the Bay >>> Libre guys to fix this already, but I can't seem to find it at the >>> moment. When it is found, it would be good to have it applied to the 4.9 >>> stable and 4.10 mainline trees. >> >> Yes, a patch was submitted. It is pending in my queue since I need to do >> a few experiments myself to determine if its the best solution possible. >> Thanks for the heads-up on need to mark it for v4.9 stable. Will do. > > The master branch of my tree should have the patch included. If you can > test and confirm it works fine on the lego platform, it will be great. > Tested "ARM: davinci: da850: fix infinite loop in clk_set_rate()" working on LEGO Mindstorms with a 4.9.0 kernel.