15.12.2020 21:22, Florian Fainelli пишет:
>
>
> On 12/15/2020 8:53 AM, Dmitry Osipenko wrote:
>> 15.12.2020 19:40, Florian Fainelli пишет:
>>>
>>>
>>> On 12/15/2020 8:17 AM, Dmitry Osipenko wrote:
>>>> 15.12.2020 19:04, Florian Fainelli пишет:
>>>>>
>>>>>
>>>>> On 12/15/2020 5:52 AM, Dmitry Osipenko wrote:
>>>>>> The tegra_uart_config of the DEBUG_LL code is now placed right at the
>>>>>> start of the .text section after commit which enabled debug output in the
>>>>>> decompressor. Tegra devices are not booting anymore if DEBUG_LL is enabled
>>>>>> since tegra_uart_config data is executes as a code. Fix the misplaced
>>>>>> tegra_uart_config storage by embedding it into the code.
>>>>>>
>>>>>> Cc: stable@xxxxxxxxxxxxxxx
>>>>>> Fixes: 2596a72d3384 ("ARM: 9009/1: uncompress: Enable debug in head.S")
>>>>>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>>>>>> ---
>>>>>> arch/arm/include/debug/tegra.S | 54 +++++++++++++++++-----------------
>>>>>> 1 file changed, 27 insertions(+), 27 deletions(-)
>>>>>
>>>>> Looks like arch/arm/include/debug/brcmstb.S would need the same
>>>>> treatment since the implementation was copied from tegra.S.
>>>>>
>>>>
>>>> Good catch, will you be able to test the brcm and make a patch?
>>>
>>> Yes, absolutely, building a kernel to test right now.
>>>
>>
>> Thank you.
>>
>> BTW, I noticed that the problem is more visible on a thumb2 kernel
>> build, i.e. you should get a more reliable hang on boot. On a non-thumb2
>> kernel the hanging behaviour seems depends on a device / bootloader. I
>> haven't tried to figure out what exactly makes the difference, perhaps
>> it should be a memory layout / state.
>
> To build with a CONFIG_THUMB2_KERNEL I had to fetch:
>
> https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=9018/2
>
> to avoid a build error, too bad this missed v5.10 final but hopefully it
> can make it soon.
The VFP fix was applied to the -next very recently, it should propagate
to v5.10 eventually.
> With CONFIG_THUMB2_KERNEL=y, I am not getting the head.S output where it
> prints the start/end of the compressed kernel:
>
> C:0x420800C0-0x4321B0E0->0x4212AB00-0x432C5B20
> Uncompressing Linux... done, booting the kernel.
> [ 0.000000] Booting Linux on physical CPU 0x0
> [ 0.000000] Linux version 5.10.0-g148842c98a24
> (fainelli@fainelli-desktop) (arm-linux-gcc (GCC) 8.3.0, GNU ld (GNU
> Binutils) 2.32) #71 SMP Tue Dec 15 09:53:09 PST 2020
>
> I am only getting:
>
> Uncompressing Linux... done, booting the kernel.
>
> Is that the same for you?
No, start/end are printed for both THUMB2 and ARM kernels here.
> Looking at the disassembly of head.o it definitively has
> brcmstb_uart_config in the .text section as the beginning just like you
> mentioned in your commit message.
>
> Disassembly of section .text:
>
> 00000000 <brcmstb_uart_config>:
> 0: 00000001 andeq r0, r0, r1
> ...
> c: 467c mov r4, pc
> e: f004 4478 and.w r4, r4, #4160749568 ; 0xf8000000
> 12: f504 4400 add.w r4, r4, #32768 ; 0x8000
> 16: 4678 mov r0, pc
> 18: 42a0 cmp r0, r4
> 1a: bf3f itttt cc
> 1c: 48d4 ldrcc r0, [pc, #848] ; (370 <LC1+0x8>)
> 1e: 4478 addcc r0, pc
> 20: 4284 cmpcc r4, r0
> 22: f044 0401 orrcc.w r4, r4, #1
> 26: bf28 it cs
> 28: f000 f9aa blcs 380 <cache_on>
>
> however after applying a fix similar to yours, we do end-up with the
> expected data embedded within the code and given brcmstb.S would be
> subject to the same issue as tegra.S, it would not hurt.
>
Have you checked whether start/end printed after applying the fix?
