[PATCH 4/4] clk: zynq: Use of_init_clk_data()

[Soren Brinkmann]

On Wed, Dec 19, 2012 at 12:30:21PM -0800, Stephen Boyd wrote:
> On 12/19/12 11:22, Soren Brinkmann wrote:
> > Hi Stephen,
> >
> > I guess Josh is the better person to talk about this, since he created the
> > patches regarding common clock for mainline, but I tried running your series
> > and ran into this:
> >
> > Unable to handle kernel NULL pointer dereference at virtual address 0000002a
> > pgd = c0004000
> > [0000002a] *pgd=00000000
> > Internal error: Oops: 5 [#1] PREEMPT ARM
> > Modules linked in:
> > CPU: 0    Tainted: G        W     (3.7.0-rc3-00025-gc11ffdd-dirty #246)
> > PC is at __clk_prepare+0x20/0x80
> > LR is at clk_prepare+0x2c/0x44
> > pc : [<c031659c>]    lr : [<c0316628>]    psr: a0000153
> > sp : ee02fdd0  ip : ee02fde8  fp : ee02fde4
> > r10: 00000000  r9 : 00000000  r8 : c0587884
> > r7 : 00000000  r6 : c05aab98  r5 : fffffffe  r4 : fffffffe
> > r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : fffffffe
> > Flags: NzCv  IRQs on  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
> > Control: 18c5387d  Table: 00004059  DAC: 00000015
> > Process swapper (pid: 1, stack limit = 0xee02e230)
> > Stack: (0xee02fdd0 to 0xee030000)
> > fdc0:                                     c05b6a18 fffffffe ee02fdfc ee02fde8
> > fde0: c0316628 c0316588 ee085400 fffffffe ee02fe24 ee02fe00 c03c1358 c0316608
> > fe00: c03c1328 ee085410 c05aab98 c05aab98 00000000 c0587884 ee02fe34 ee02fe28
> > fe20: c026a5c0 c03c1334 ee02fe5c ee02fe38 c0268f50 c026a5a8 c026a7b8 c0313ac0
> > fe40: ee085410 ee085410 ee085444 c05aab98 ee02fe7c ee02fe60 c02691c0 c0268e18
> > fe60: c0269150 c05aab98 c0269150 00000000 ee02fea4 ee02fe80 c0267320 c026915c
> > fe80: ee00948c ee096df0 c021e02c c05aab98 ed9a0bc0 c05ab3a8 ee02feb4 ee02fea8
> > fea0: c0268a28 c02672d0 ee02fee4 ee02feb8 c0268408 c0268a0c c04b56d1 00000000
> > fec0: ee02fee4 c05aab98 c0565e60 00000000 0000006f c0587884 ee02ff14 ee02fee8
> > fee0: c0269990 c0268340 00000000 00000000 c0565e60 00000000 0000006f c0587884
> > ff00: 00000000 00000000 ee02ff24 ee02ff18 c026a9cc c02698f0 ee02ff3c ee02ff28
> > ff20: c0565e84 c026a984 ee02e000 ee02ff40 ee02ff74 ee02ff40 c00086f8 c0565e6c
> > ff40: c04f72e4 00000000 ee02ff74 00000006 00000006 c0571dac c0571d8c 0000006f
> > ff60: c0587884 00000000 ee02ffac ee02ff78 c03bf9c4 c0008664 00000006 00000006
> > ff80: c05511a8 00000000 ee02ffac 00000000 c03bf8cc 00000000 00000000 00000000
> > ffa0: 00000000 ee02ffb0 c000ea98 c03bf8d8 00000000 00000000 00000000 00000000
> > ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 0158ec21 0eced1ff
> > [<c031659c>] (__clk_prepare+0x20/0x80) from [<c0316628>] (clk_prepare+0x2c/0x44)
> > [<c0316628>] (clk_prepare+0x2c/0x44) from [<c03c1358>] (xuartps_probe+0x30/0x1ac
> > )
> > [<c03c1358>] (xuartps_probe+0x30/0x1ac) from [<c026a5c0>] (platform_drv_probe+0x
> > 24/0x28)
> > [<c026a5c0>] (platform_drv_probe+0x24/0x28) from [<c0268f50>] (driver_probe_devi
> > ce+0x144/0x344)
> > [<c0268f50>] (driver_probe_device+0x144/0x344) from [<c02691c0>] (__driver_attac
> > h+0x70/0x94)
> > [<c02691c0>] (__driver_attach+0x70/0x94) from [<c0267320>] (bus_for_each_dev+0x5
> > c/0x8c)
> > [<c0267320>] (bus_for_each_dev+0x5c/0x8c) from [<c0268a28>] (driver_attach+0x28/
> > 0x30)
> > [<c0268a28>] (driver_attach+0x28/0x30) from [<c0268408>] (bus_add_driver+0xd4/0x
> > 254)
> > [<c0268408>] (bus_add_driver+0xd4/0x254) from [<c0269990>] (driver_register+0xac
> > /0x14c)
> > [<c0269990>] (driver_register+0xac/0x14c) from [<c026a9cc>] (platform_driver_reg
> > ister+0x54/0x68)
> > [<c026a9cc>] (platform_driver_register+0x54/0x68) from [<c0565e84>] (xuartps_ini
> > t+0x24/0x44)
> > [<c0565e84>] (xuartps_init+0x24/0x44) from [<c00086f8>] (do_one_initcall+0xa0/0x
> > 170)
> > [<c00086f8>] (do_one_initcall+0xa0/0x170) from [<c03bf9c4>] (kernel_init+0xf8/0x
> > 2ac)
> > [<c03bf9c4>] (kernel_init+0xf8/0x2ac) from [<c000ea98>] (ret_from_fork+0x14/0x20
> > )
> > Code: e8bd4000 e2504000 01a05004 0a000015 (e594302c) 
> > ---[ end trace 1b75b31a2719ed1d ]---
> > Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
> >
> >
> > A probably unique thing I do is, I set the status of uart0 to disabled. This way
> > I can reuse my rootfs which does not run getty on ttyPS1. And this worked fine
> > before.
> >
> 
> Thanks for testing. It seems that clocks are failing to register. Please
> try this patch.
> 
> --->8-----
> 
> diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
> index 2be22a2..2734715 100644
> --- a/drivers/tty/serial/xilinx_uartps.c
> +++ b/drivers/tty/serial/xilinx_uartps.c
> @@ -948,9 +948,9 @@ static int xuartps_probe(struct platform_device *pdev)
>         struct clk *clk;
> 
>         clk = of_clk_get(pdev->dev.of_node, 0);
> -       if (!clk) {
> -               dev_err(&pdev->dev, "no clock specified\n");
> -               return -ENODEV;
> +       if (IS_ERR(clk)) {
> +               dev_err(&pdev->dev, "failed to get clock\n");
> +               return PTR_ERR(clk);
>         }
> 
>         rc = clk_prepare_enable(clk);
> 
Sorry, I messed something up. I tried to test this patch and my config didn't
build anymore. I rebuilt after making clean and now I'm seeing the same warnings
Josh already reported (w/o this patch applied).
Sorry for causing confusion.

I then cherry-picked Josh's commit (it's in the Xilinx arm-next tree btw. (sha1:
74cad6042156c30fe64d3226e041c77139ae8bcf)) and also added your proposed patch
from above. These all consistently gain the same results showing the warnings.

And you're right with that some clocks are not registered:
zynq:/debug/clk # lst
   .
   |-orphans
   |-ps_clk
   |---armpll
   |-----cpu_6x4x
   |---ddrpll
   |---iopll
   |-----uart0_ref_clk

	Soren