[PATCH] ARM: OMAP: Fix map_io for Amstrad E3

[aaro.koskinen@iki.fi (Aaro Koskinen)]

Hi,

On Wed, 9 Nov 2011, Tony Lindgren wrote:
> * Aaro Koskinen <aaro.koskinen@iki.fi> [111109 15:25]:
>> On 10.11.2011, at 1.39, Russell King - ARM Linux wrote:
>>> On Wed, Nov 09, 2011 at 03:25:25PM -0800, Tony Lindgren wrote:
>>>> Commit 7b88e62f5d219a86d81bdf4388012c97dc42e8f8 (ARM: OMAP1: Use
>>>> generic
>>>> map_io, init_early and init_irq) changed omap1 to use generic map_io.
>>>>
>>>> Looks like I missed one board though. Fix this by adding a custom
>>>> map_io for Amstrad E3.
>>>>
>>>> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
>>>> Signed-off-by: Tony Lindgren <tony@atomide.com>
>>>>
>>>> ---
>>>> Untested, does this help?
>>>> --- a/arch/arm/mach-omap1/board-ams-delta.c
>>>> +++ b/arch/arm/mach-omap1/board-ams-delta.c
>>>> @@ -302,8 +302,6 @@ static void __init ams_delta_init(void)
>>>> 	omap_cfg_reg(J19_1610_CAM_D6);
>>>> 	omap_cfg_reg(J18_1610_CAM_D7);
>>>>
>>>> -	iotable_init(ams_delta_io_desc, ARRAY_SIZE(ams_delta_io_desc));
>>>> -
>>>
>>> This is definitely wrong.  Using iotable_init() after map_io has
>>> returned
>>> has (and remains) a serious bug - doing so may _appear_ to work
>>> but as it
>>> doesn't obtain its memory from the standard kernel memory
>>> allocators, it
>>> will lead to duplicate usage of that memory.
>>
>> Also, the patch did not help. It still hangs like before.
>
> Hmm that patch is needed for sure but sounds like there's also
> something else wrong.. Can you try to git bisect it?

I found it impossible to bisect, but there are two issues I found:

1) earlyconsole turns into garbage in omap1_clk_init() unless I do
the following:

diff --git a/arch/arm/mach-omap1/clock_data.c b/arch/arm/mach-omap1/clock_data.c
index 92400b9..b9ce2ad 100644
--- a/arch/arm/mach-omap1/clock_data.c
+++ b/arch/arm/mach-omap1/clock_data.c
@@ -774,14 +774,6 @@ int __init omap1_clk_init(void)
  	int crystal_type = 0; /* Default 12 MHz */
  	u32 reg, cpu_mask;

-#ifdef CONFIG_DEBUG_LL
-	/*
-	 * Resets some clocks that may be left on from bootloader,
-	 * but leaves serial clocks on.
-	 */
-	omap_writel(0x3 << 29, MOD_CONF_CTRL_0);
-#endif
-
  	/* USB_REQ_EN will be disabled later if necessary (usb_dc_ck) */
  	reg = omap_readw(SOFT_REQ_REG) & (1 << 4);
  	omap_writew(reg, SOFT_REQ_REG);

2) By using the above hack, I could see the actual crash:

Uncompressing Linux... done, booting the kernel.
[    0.000000] Initializing cgroup subsys cpu
[    0.000000] Linux version 3.2.0-rc1-e3 (aaro at dell) (gcc version 4.6.1 (GCC) ) #9 PREEMPT Thu Nov 10 23:48:23 EET 2011
[    0.000000] CPU: ARM925T [54029252] revision 2 (ARMv4T), cr=0000317f
[    0.000000] CPU: VIVT data cache, VIVT instruction cache
[    0.000000] Machine: Amstrad E3 (Delta)
[    0.000000] bootconsole [earlycon0] enabled
[    0.000000] Memory policy: ECC disabled, Data cache writethrough
[    0.000000] OMAP1510
[    0.000000]  revision 2 handled as 15xx id: bc058c9b93111a16
[    0.000000] Clocks: ARM_SYSST: 0x1000 DPLL_CTL: 0x2cb3 ARM_CKCTL: 0x250e
[    0.000000] ------------[ cut here ]------------
[    0.000000] kernel BUG at arch/arm/plat-omap/sram.c:226!
[    0.000000] Internal error: Oops - undefined instruction: 0 [#1] PREEMPT
[    0.000000] Modules linked in:
[    0.000000] CPU: 0    Not tainted  (3.2.0-rc1-e3 #9)
[    0.000000] PC is at omap_sram_reprogram_clock+0x28/0x30
[    0.000000] LR is@omap1_select_table_rate+0x88/0xb4
[    0.000000] pc : [<c001b0c4>]    lr : [<c0019f54>]    psr: 600000d3
[    0.000000] sp : c035bf10  ip : c035bf20  fp : c035bf1c
[    0.000000] r10: c035bfd4  r9 : 54029252  r8 : c03f8120
[    0.000000] r7 : c0362b50  r6 : 00b71b00  r5 : c03873cc  r4 : c0362b40
[    0.000000] r3 : 00000000  r2 : c0362b40  r1 : 0000010a  r0 : 00002cb0
[    0.000000] Flags: nZCv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
[    0.000000] Control: 0000317f  Table: 10004000  DAC: 00000017
[    0.000000] Process swapper (pid: 0, stack limit = 0xc035a270)
[    0.000000] Stack: (0xc035bf10 to 0xc035c000)
[    0.000000] bf00:                                     c035bf3c c035bf20 c0019f54 c001b0ac
[    0.000000] bf20: 00001000 00002cb3 00000004 c035ed4c c035bf74 c035bf40 c033ea24 c0019edc
[    0.000000] bf40: c02f526c 00000002 00000015 bc058c9b 93111a16 c035335c 02000000 c035ed4c
[    0.000000] bf60: c035ed4c c03f8120 c035bf84 c035bf78 c00194c4 c033e8ec c035bfc4 c035bf88
[    0.000000] bf80: c033bc24 c00194a0 c035bf90 c035bf98 00000000 00000000 00000000 00000000
[    0.000000] bfa0: 00000001 00000000 c0354678 c035ece4 10004000 103532f4 c035bff4 c035bfc8
[    0.000000] bfc0: c0338574 c033b598 00000000 00000000 00000000 c035467c 0000317d c035c03c
[    0.000000] bfe0: c0354678 c035ece4 00000000 c035bff8 10008040 c0338508 00000000 00000000
[    0.000000] Backtrace:
[    0.000000] [<c001b09c>] (omap_sram_reprogram_clock+0x0/0x30) from [<c0019f54>] (omap1_select_table_rate+0x88/0xb4)
[    0.000000] [<c0019ecc>] (omap1_select_table_rate+0x0/0xb4) from [<c033ea24>] (omap1_clk_init+0x148/0x334)
[    0.000000]  r7:c035ed4c r6:00000004 r5:00002cb3 r4:00001000
[    0.000000] [<c033e8dc>] (omap1_clk_init+0x0/0x334) from [<c00194c4>] (omap1_init_early+0x34/0x48)
[    0.000000]  r8:c03f8120 r7:c035ed4c r6:c035ed4c r5:02000000 r4:c035335c
[    0.000000] [<c0019490>] (omap1_init_early+0x0/0x48) from [<c033bc24>] (setup_arch+0x69c/0x79c)
[    0.000000] [<c033b588>] (setup_arch+0x0/0x79c) from [<c0338574>] (start_kernel+0x7c/0x2f4)
[    0.000000] [<c03384f8>] (start_kernel+0x0/0x2f4) from [<10008040>] (0x10008040)
[    0.000000]  r7:c035ece4 r6:c0354678 r5:c035c03c r4:0000317d
[    0.000000] Code: 0a000002 e1a0e00f e12fff13 e89da800 (e7f001f2)
[    0.000000] ---[ end trace 1b75b31a2719ed1c ]---

The BUG_ON() in omap_sram_reprogram_clock() triggers, because
it's called before omap_sram_init(). If I comment out the code in
omap_sram_reprogram_clock(), the board boots up.

A.