[PATCH v1 0/3] Transition pxa25x clock to common clocks

Dmitry Eremin-Solenikov [off-list ref] writes:

Hello,

Tested in qemu (pxa25x target).

Excellent.

0) Had to revert 23c4a3a5212701ad34bd30591fa33d7bacef9c5f to get kernel
to build for pxa25x + pxa27x.

Yes, good move.

1) I got the following backtrace early in the boot:

Division by zero in kernel.
CPU: 0 PID: 0 Comm: swapper Not tainted 3.18.0-rc2-00011-g7805b78 #97
[<c000e028>] (unwind_backtrace) from [<c000c0b4>] (show_stack+0x10/0x14)
[<c000c0b4>] (show_stack) from [<c01a3af0>] (Ldiv0+0x8/0x10)
[<c01a3af0>] (Ldiv0) from [<c029bb9c>] (clk_pxa25x_memory_get_rate+0x28/0x30)
[<c029bb9c>] (clk_pxa25x_memory_get_rate) from [<c029b114>]
(clk_composite_recalc_rate+0x20/0x24)
[<c029b114>] (clk_composite_recalc_rate) from [<c0299888>]
(__clk_init+0x1d0/0x4e8)
[<c0299888>] (__clk_init) from [<c0299d24>] (clk_register+0x100/0x1c4)
[<c0299d24>] (clk_register) from [<c029b518>]
(clk_register_composite+0x17c/0x250)
[<c029b518>] (clk_register_composite) from [<c04cecd4>]
(pxa25x_clocks_init+0x194/0x240)
[<c04cecd4>] (pxa25x_clocks_init) from [<c04c048c>] (pxa_timer_init+0x18/0x64)
[<c04c048c>] (pxa_timer_init) from [<c04bde88>] (time_init+0x1c/0x2c)
[<c04bde88>] (time_init) from [<c04bbb14>] (start_kernel+0x268/0x3e8)
[<c04bbb14>] (start_kernel) from [<a0008040>] (0xa0008040)

It might be due to something being not emulated properly, but I'd
suggest to add a check
anyway.

You're right about that part. According to the specification, the "M" multiplier
in CCCR can only be 1, 2, or 3. 0 is a reserved value which should never happen,
and if it happens, hardware is already lost.
I don't want to be that defensive in this code unless it blocks something for
good.

2) sa1100-rtc could not find a clock and thus failed to be probed.

Ha I'll check that, thanks.

3) Had to patch tc6393xb driver to call
clk_prepare_enable/clk_disable_unprepare -
  will submit a patch shortly.

Good catch.

4) Got an issue with IrDA driver - it gets -ENODEV for UARTCLK clock

I'll check that too. It's probable I either forgot a clock or mispelled a
clock.

Thanks for the test Dmitry.

Cheers.

-- 
Robert