Re: [PATCH v2 1/1] cxl/test: Update mock dev array before calling platform_device_add()

[Li Ming <ming.li@zohomail.com>]

在 2026/5/21 15:25, Alison Schofield 写道:
> On Wed, May 20, 2026 at 08:14:57PM +0800, Li Ming wrote:
>> CXL test environment hits the following error sometimes.
>>
>>   cxl_mem mem9: endpoint7 failed probe
>>
>> All mock memdevs are platform firmware devices added by cxl_test module,
>> and cxl_test module also provides a platform device driver for them to
>> create a memdev device to CXL subsystem. cxl_test module uses
>> cxl_rcd/mem_single/mem arrays to store different types of mock memdevs.
>> CXL drivers calls registered mock functions for a mock memdev by
>> checking if a given memdev is in these arrays.
>>
>> When cxl_test module adds these mock memdevs, it always calls
>> platform_device_add() before adding them to a suitable mock memdev
>> array. However, there is a small window where CXL drivers calls mock
>> function for a added memdev before it added to a mock memdev array. In
>> above case, cxl endpoint driver considers a added memdev was not a mock
>> memdev, then calling devm_cxl_endpoint_decoders_setup() for it rather
>> than mock_endpoint_decoders_setup().
>>
>> An appropriate solution is that adding a new mock device to a mock
>> device array before calling platform_device_add() for it. It can
>> guarantee the new mock device is visible to CXL subsystem.
>>
>> This patch introduces a new helped called cxl_mock_platform_device_add()
>> to handle the issue, and uses the function for all mock devices addition.
>>
> Reviewed-by: Alison Schofield <alison.schofield@intel.com>

Hi Alison,


I missed that you mentioned putting platform_device_alloc() into the 
helper. I will send out v3 for that.


Ming

>
>
>> Fixes: 3a2b97b3210b ("cxl/test: Improve init-order fidelity relative to real-world systems")
>> Signed-off-by: Li Ming <ming.li@zohomail.com>
>> ---
>> Changes from v1:
>> - Rebase to v7.1-rc4.
>> - Introduce a new helper to handle the issue. (Alison)
>> - Use new helper for all mock device addition.
>> ---
>>   tools/testing/cxl/test/cxl.c | 105 ++++++++++++++---------------------
>>   1 file changed, 43 insertions(+), 62 deletions(-)
>>