2018-04-05 16:36 GMT+02:00 Sekhar Nori <nsekhar@xxxxxx>: > On Thursday 05 April 2018 07:14 PM, Bartosz Golaszewski wrote: >> 2018-04-05 15:09 GMT+02:00 Sekhar Nori <nsekhar@xxxxxx>: >>> Hi Bartosz, >>> >>> On Friday 09 February 2018 10:18 PM, Michael Turquette wrote: >>>> On Fri, Feb 9, 2018 at 8:22 AM, Bartosz Golaszewski <brgl@xxxxxxxx> wrote: >>>>> 2018-01-08 3:17 GMT+01:00 David Lechner <david@xxxxxxxxxxxxxx>: >>> >>>>> Hi David, >>>>> >>>>> I've been working on moving the genpd code from its own driver to the >>>>> psc one. I couldn't get the system to boot though and problems >>>>> happened very early in the boot sequence. I struggled to figure out >>>>> what's happening, but eventually I noticed that psc uses >>>>> CLK_OF_DECLARE() to initialize clocks. The functions registered this >>>>> way are called very early in the boot sequence, way before >>>>> late_initcall() in which the genpd framework is initialized. This of >>> >>> late_initcall() is too late for genpd to be initialized. As you may have >>> seen with the latest set of patches, we have problems with timer >>> initialization. After converting to platform devices, PSC and PLL clocks >>> get initialized post time_init(). We are working that around using >>> fixed-clocks, which hopefully will work (I still need to test many of >>> the affected platforms). >>> >>> Can you please reply with the exact issue you faced with genpd framework >>> initialization so we do have that on record. >>> >> >> The exact issue manifested itself in a NULL-pointer dereference panic >> when I tried moving the genpd code I had initially implemented as a >> separate platform driver to what I believe was v6 or v7 of David's >> series (before the psc driver became a platform driver, when it was >> still using CLK_OF_DECLARE()). When I had tested a simple conversion >> of that version to a platform_driver, genpd worked fine. >> >> I don't have the stack traces from these panics, but I recall some >> debugfs functions being involved and the genpd late_initcalls are >> related to debugfs. Looking at it now I don't see how exactly it could >> fail though. > > Do you have the code where you faced the problem stashed somewhere? I am > not (yet) advocating going back to CLK_OF_DECLARE(). But there is a > definite issue with timer being ready when not using CLK_OF_DECLARE(). > So, I want to make sure there the reason why we are going down the > platform device path is a amply clear. > > Thanks, > Sekhar Yes, you can still find it on my github[1]. Bart [1] github.com:brgl/linux.git topic/davinci-genpd-final-v2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
