[PATCH V2] spi: Update speed/mode on change

[Marek Vasut]

On 3/29/21 4:40 AM, Marek Vasut wrote:
> On 3/29/21 4:09 AM, Marek Vasut wrote:
>> On 3/29/21 3:59 AM, Tom Rini wrote:
>>> On Mon, Mar 29, 2021 at 03:32:51AM +0200, Marek Vasut wrote:
>>>> On 3/28/21 11:30 PM, Tom Rini wrote:
>>>>> On Fri, Feb 26, 2021 at 03:21:24PM +0100, Marek Vasut wrote:
>>>>>
>>>>>> The spi_get_bus_and_cs() may be called on the same bus and chipselect
>>>>>> with different frequency or mode. This is valid usecase, but the code
>>>>>> fails to notify the controller of such a configuration change. Call
>>>>>> spi_set_speed_mode() in case bus frequency or bus mode changed to let
>>>>>> the controller update the configuration.
>>>>>>
>>>>>> The problem can easily be triggered using the sspi command:
>>>>>> => sspi 0:0 at 1000
>>>>>> => sspi 0:0 at 2000
>>>>>> Without this patch, both transfers happen at 1000 Hz. With this 
>>>>>> patch,
>>>>>> the later transfer happens correctly at 2000 Hz.
>>>>>>
>>>>>> Signed-off-by: Marek Vasut <marex at denx.de>
>>>>>> Cc: Jagan Teki <jagan at amarulasolutions.com>
>>>>>> Cc: Patrick Delaunay <patrick.delaunay at st.com>
>>>>>
>>>>> So, very reliably I can make:
>>>>> https://source.denx.de/u-boot/u-boot/-/jobs/245517
>>>>> happen locally as well building with clang.  It's not obvious to me 
>>>>> why
>>>>> the test now fails however.
>>>>
>>>> Can you please be more specific / clear ? I have no idea what those 300
>>>> lines of cryptic output mean, nor what are you trying to say by the 
>>>> above,
>>>> sorry.
>>>
>>> If you build with clang, for sandbox, and run the tests, U-Boot crashes
>>> in the unit tests that you start with "ut dm".
>>
>> And that is related to this patch somehow ? How ?
> 
> ... after further discussion off-list to get a better test case 
> description ...
> 
> It seems the problem is in sound_beep() and it is unrelated to this 
> patch, as the same problem happens with / without this patch being 
> applied, on:
> 
> a7d3ac61482 ("Merge branch '2021-03-28-assorted-bugfixes'")
> 
> $ clang --version
> Debian clang version 11.0.1-2
> ...
> $ make CC=clang HOSTCC=clang sandbox_defconfig
> $ make CC=clang HOSTCC=clang
> $ gdb --args ./u-boot -d arch/sandbox/dts/test.dtb
> => ut dm
> ...
> Program received signal SIGSEGV, Segmentation fault.
> dlfree (mem=<optimized out>, mem at entry=0x15c19c50) at 
> common/dlmalloc.c:1623
> 1623      if (!(inuse_bit_at_offset(next, nextsz)))   /* consolidate 
> forward */
> (gdb) bt
> #0  dlfree (mem=<optimized out>, mem at entry=0x15c19c50) at 
> common/dlmalloc.c:1623
> #1  0x00000000004759e3 in sound_beep (dev=0x15c05580, msecs=<optimized 
> out>, frequency_hz=100)
>     at drivers/sound/sound-uclass.c:118

Tom, any further comments ? It seems your claim that this bugfix is 
causing problems with clang is not correct, so I think it should still 
be applied to v2021.04 , unless you can provide more details about the 
clang problem ?