On Friday 15 March 2013 09:50 PM, Tony Lindgren wrote: > * Rajendra Nayak <rnayak@xxxxxx> [130315 05:31]: >> On Thursday 14 March 2013 10:36 PM, Tony Lindgren wrote: >>> * Rajendra Nayak <rnayak@xxxxxx> [130314 05:44]: >>>> OMAP clock inits happen quite early, even before the slab is available. >>>> As part of the clock init, the common clock core tries to cache parent >>>> pointers (if not passed by the caller registering the clock) which >>>> fails in case of OMAP since the slab isn't initied. >>>> Without CONFIG_DEBUG_SLAB enabled, this just results in the common clock core >>>> retrying the caching attempt at some point later. >>>> However with CONFIG_DEBUG_SLAB enabled this results in a BUG() as reported >>>> in the link below by Tony.. >>>> http://www.mail-archive.com/linux-omap@xxxxxxxxxxxxxxx/msg85932.html >>>> >>>> Fix this by passing static parent pointers to the common clock core >>>> while registering clocks. >>> >>> I wonder if we could easily fix this by initializing only some of the >>> clocks that early? >> >> We actually don't need any clocks that early (I mean even before slab init) >> We only need them before timer init. > > Yes and only the timer clocks at that point. The others could be initialized > later on so we get console error messages without having to turn on DEBUG_LL > and earlyprintk. but that wouldn't be possible with the hwmod dependency on clocks. We would need to move the hwmod inits further down too. > >> This isn't something specific to OMAP so I started looking at what others >> in drivers/clk seem to do. >> >> I found imx, spear, mvebu all do their clk inits within .init_time callbacks. >> tegra seems to even do it within .init_irq callback. >> >> Either one would work for us too :) > > Well I suggest init_irq as that's when we need the first clocks for timer. For which platforms? I instead see them being needed only by init_timer, so was thinking thats a better place instead. For the -rc fix to fix the crash with DEBUG_SLAB, is it fine if I move *all* clock inits down to init_timer (or init_irq). Splitting clocks alone would not work for now, without hwmod being moved down also. > > Regards, > > Tony > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
