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

[Marek Vasut]

On 4/1/21 1:41 AM, Simon Glass wrote:
> Hi Marek,
> 
> On Thu, 1 Apr 2021 at 12:19, Marek Vasut <marex at denx.de> wrote:
>>
>> On 4/1/21 12:50 AM, Simon Glass wrote:
>>> Hi Marek,
>>>
>>> On Thu, 1 Apr 2021 at 11:39, Marek Vasut <marex at denx.de> wrote:
>>>>
>>>> On 3/31/21 11:45 PM, Tom Rini wrote:
>>>>> On Wed, Mar 31, 2021 at 10:05:28PM +0200, Marek Vasut wrote:
>>>>>> On 3/31/21 9:40 PM, Tom Rini wrote:
>>>>>>> On Wed, Mar 31, 2021 at 03:26:27PM -0400, Tom Rini wrote:
>>>>>>>> On Wed, Mar 31, 2021 at 09:18:28PM +0200, Marek Vasut wrote:
>>>>>>>>> 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 ?
>>>>>>>>
>>>>>>>> There's at least a few funny things going on.  Yes, apparently outside
>>>>>>>> of CI building sandbox with clang and running the tests manually crashes
>>>>>>>> in sound, before it gets to the SPI tests.  Except when it crashes on
>>>>>>>> the SPI tests instead, which I did get to happen once.  So there's some
>>>>>>>> sort of use-after-free or similar bug around here somewhere, similar to
>>>>>>>> how we can't use the -fstack-protector patch as it exposes other real
>>>>>>>> problems that need to be fixed first.
>>>>>>>>
>>>>>>>> So, I'll see if with a new tag and a few other changes having been made
>>>>>>>> we once again get to the point where your patch doesn't trigger this
>>>>>>>> issue.  But since it's also not a regression fix, if no one can figure
>>>>>>>> out what to do about fixing what clang shows us, then it can wait for
>>>>>>>> v2021.07.
>>>>>>>
>>>>>>> Nope, still gets things to blow up:
>>>>>>> https://source.denx.de/u-boot/u-boot/-/jobs/246848
>>>>>>>
>>>>>>> and yes, it would be nice if when the reason a pytest fails is that
>>>>>>> U-Boot crashed, it would say something more clear than "OSError: [Errno
>>>>>>> 5] Input/output error" and you have to know that means U-Boot died.
>>>>>>
>>>>>> Can you please provide a detailed test case how to reproduce this ?
>>>>>> So far I don't have one, the only test description I got is "install random
>>>>>> version of clang, run ut dm and it fails", but that kind of imprecise test
>>>>>> description is really not useful. Please provide more specific instructions.
>>>>>
>>>>> Yes, follow what CI does.  It's done in a container, so you can have the
>>>>> exact same runtime and the tests are in .azure-pipelines.yml and
>>>>> .gitlab-ci.yml or if you look at
>>>>> https://source.denx.de/u-boot/u-boot/-/jobs/246848/raw you can see the
>>>>> commands in there.
>>>>
>>>> Can you please provide me the exact commands to run to reproduce this
>>>> problem ? I just spent a lot of time trying to find this one single
>>>> command in a wall of text, "ut dm spi_find", which I think is the one
>>>> failing for you ? It seems to work for me with and without the patch:
>>>>
>>>> $ ./u-boot -d arch/sandbox/dts/test.dtb
>>>> sandbox: starting...
>>>>
>>>>
>>>> U-Boot 2021.04-rc5-00005-g583b6858733 (Apr 01 2021 - 00:34:09 +0200)
>>>>
>>>> Model: sandbox
>>>> DRAM:  128 MiB
>>>> WDT:   Started with servicing (60s timeout)
>>>> MMC:   mmc2: 2 (SD), mmc1: 1 (SD), mmc0: 0 (SD)
>>>> In:    serial
>>>> Out:   vidconsole
>>>> Err:   vidconsole
>>>> Model: sandbox
>>>> SCSI:
>>>> Net:   eth0: eth at 10002000, eth5: eth at 10003000, eth3: sbe5, eth6:
>>>> eth at 10004000
>>>> Hit any key to stop autoboot:  0
>>>>
>>>> Without patch
>>>> => ut dm spi_find
>>>> Test: dm_test_spi_find: spi.c
>>>> test/dm/spi.c:71, dm_test_spi_find(): 0 == spi_get_bus_and_cs(busnum,
>>>> cs, speed, mode, "jedec_spi_nor", "name", &bus, &slave): Expected 0x0
>>>> (0), got 0xfffffffb (-5)
>>>> Test: dm_test_spi_find: spi.c (flat tree)
>>>> test/dm/spi.c:71, dm_test_spi_find(): 0 == spi_get_bus_and_cs(busnum,
>>>> cs, speed, mode, "jedec_spi_nor", "name", &bus, &slave): Expected 0x0
>>>> (0), got 0xfffffffb (-5)
>>>> Failures: 2
>>>>
>>>> With patch
>>>> => ut dm spi_find
>>>> Test: dm_test_spi_find: spi.c
>>>> test/dm/spi.c:71, dm_test_spi_find(): 0 == spi_get_bus_and_cs(busnum,
>>>> cs, speed, mode, "jedec_spi_nor", "name", &bus, &slave): Expected 0x0
>>>> (0), got 0xfffffffb (-5)
>>>> Test: dm_test_spi_find: spi.c (flat tree)
>>>> test/dm/spi.c:71, dm_test_spi_find(): 0 == spi_get_bus_and_cs(busnum,
>>>> cs, speed, mode, "jedec_spi_nor", "name", &bus, &slave): Expected 0x0
>>>> (0), got 0xfffffffb (-5)
>>>> Failures: 2
>>>
>>> The Python test sets up a SPI-flash file (spi.bin) that is needed by the test.
>>>
>>> I use this alias:
>>>
>>> # Run a pytest on sandbox
>>> # $1: Name of test to run (optional, else run all)
>>> function pyt {
>>>      test/py/test.py -B sandbox --build-dir /tmp/b/sandbox ${1:+"-k $1"}
>>> }
>>>
>>> then 'pyt spi_find'
>>>
>>> Once you've done that once you can do what you had before:
>>>
>>> ./u-boot -T
>>
>> Do you also have a minimal test which does not depend on pytest at all ?
>> A testcase for a bug should be minimal and as simple as possible, it
>> shouldn't depend on all kinds of variables which are only adding
>> complexity and confusion.
> 
> There is quite a bit more documentation languishing in the -next branch, e.g.:
> 
> https://github.com/u-boot/u-boot/blob/next/doc/develop/tests_sandbox.rst
> 
> The C SPI tests could perhaps be updated to automatically create the
> spi.bin file, but several of them share it, so it would need to be a
> shared function.
> 
> I certainly only used pytest when needed, hence the substantial effort
> I made to document how to run sandbox tests directly, but I should
> point out that pytest is the overall framework that we use.

Surely for the sake of trivial test , spi.bin file can be generated 
manually using e.g. dd ?