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

[Marek Vasut]

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.