Messages in this thread |  | | From | Bartosz Golaszewski <> | Date | Thu, 5 Apr 2018 15:44:06 +0200 | Subject | Re: [PATCH v5 12/44] clk: davinci: Add platform information for TI DA850 PSC |
| |
2018-04-05 15:09 GMT+02:00 Sekhar Nori <nsekhar@ti.com>: > 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@bgdev.pl> wrote: >>> 2018-01-08 3:17 GMT+01:00 David Lechner <david@lechnology.com>: > >>> 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.
Best regards, Bartosz
|  |