On Thu, Apr 16, 2015 at 10:37:19PM +0200, Sebastian Hesselbarth wrote: > On 16.04.2015 18:17, Michael Welling wrote: > >On Thu, Apr 16, 2015 at 07:32:32AM +0300, Tero Kristo wrote: > >>On 04/15/2015 11:51 PM, Michael Welling wrote: > >>>On Wed, Apr 15, 2015 at 01:45:53PM -0700, Mike Turquette wrote: > >>>>On Wed, Apr 15, 2015 at 12:47 PM, Michael Welling <mwelling@xxxxxxxx> wrote: > [...] > >>>>>There is still an issue with the si5351. > >>>>> > >>>>>I had to comment out the clk_put here for the frequency to show up: > >>>>>http://lxr.free-electrons.com/source/drivers/clk/clk-si5351.c#L1133 > >>>>> > >>>>>Ideas? > >>>> > >>>>What is the most recent upstream commit that you are based on? > >>> > >>>I am working from 4.0.0-rc7. > >>> > >>>7b43b47373d40d557cd7e1a84a0bd8ebc4d745ab > >> > >>Hmm, I wonder why si5351 calls clk_put immediately after of_clk_get > >>in the first place, as far as I understand this destroys the clock > >>handle, which is still being used later in the code. > > > >Not sure how this ever worked. This has been in the code since the > >initial commit. > > The reason it worked before may be related with recent rework of > clk_put() itself and clk cookies instead of pointers. I lost track on > the recent clk subsystem changes here, sorry. > > However, droping the clk immediately surely isn't right. > The thing is, we can remove the clk_put() just because there is no > _remove() for that driver. I remember that back in the days the driver > was mainlined, clk removal wasn't too easy. > > FWIW, as soon as _remove() support will be added by someone, we'll have > to rethink passing struct clk* by platform_data or at least > double-check if we ever used [of_]clk_get() to obtain it. > > Mind to send a patch removing the clk_put() on !IS_ERR and add a proper > error path instead? While of_clk_get() is the only calls that need > cleanup on error in si5351_dt_parse() we should probably move that > calls to the end of this function. Otherwise we'd also have to cleanup > on every of_parse_foo() failure. What would be the proper error path? What cleanup is required? It should be noted that there are more deep rooted issues with the driver that I have noticed. For one the driver behaves differently if the debugging is on and when it is off. Here is what the kernel reports with debugging off: root@som3517-som200:~# cat /sys/kernel/debug/clk/clk_summary clock enable_cnt prepare_cnt rate accuracy phase ---------------------------------------------------------------------------------------- ref27 0 0 27000000 0 0 xtal 0 0 27000000 0 0 pllb 0 0 599999994 0 0 ms0 0 0 12499999 0 0 clk0 0 0 12499999 0 0 plla 0 0 599999994 0 0 ms2 0 0 8219178 0 0 clk2 0 0 8219178 0 0 ms1 0 0 94117646 0 0 clk1 0 0 94117646 0 0 Here is what the kernel reports with debugging on: clock enable_cnt prepare_cnt rate accuracy phase ---------------------------------------------------------------------------------------- ref27 0 0 27000000 0 0 xtal 0 0 27000000 0 0 pllb 0 0 884736000 0 0 ms0 0 0 18432000 0 0 clk0 0 0 18432000 0 0 plla 0 0 897023997 0 0 ms2 0 0 12287999 0 0 clk2 0 0 12287999 0 0 ms1 0 0 140709646 0 0 clk1 0 0 140709646 0 0 Note this is with the following devicetree entry: si5351: clock-generator { #address-cells = <1>; #size-cells = <0>; #clock-cells = <1>; compatible = "silabs,si5351a-msop"; reg = <0x60>; status = "okay"; /* connect xtal input to 27MHz reference */ clocks = <&ref27>; /* connect xtal input as source of pll0 and pll1 */ silabs,pll-source = <0 0>, <1 0>; clkout0: clkout0 { reg = <0>; silabs,drive-strength = <8>; silabs,multisynth-source = <1>; silabs,clock-source = <0>; silabs,pll-master; clock-frequency = <18432000>; }; clkout1: clkout1 { reg = <1>; silabs,drive-strength = <8>; silabs,multisynth-source = <0>; silabs,clock-source = <0>; clock-frequency = <8000000>; }; clkout2: clkout2 { reg = <2>; silabs,drive-strength = <8>; silabs,multisynth-source = <0>; silabs,clock-source = <0>; silabs,pll-master; clock-frequency = <12288000>; }; }; I am losing hope that this driver is stable enough to even use in production. > > Sebastian > -- 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
