Inconsistent ethernet RX descriptor queue when using context descriptor

[JLehm]

The following bug occurs in the stm32h7xx_hal_eth library:

When a feature of the ehernet peripheral is enabled which causes the DMA to use RX context descriptors, for example the ieee1588 timestamping unit, this leads to an inconsistent state of the RX descriptor list.

I discovered that this is caused by the HAL_ETH_BuildRxDescriptors function which does not clear the own bit of the context descriptor and does not reset the context descriptor in the descriptor list.

The following changes solve the problem:

line 1159

if(descscan < (dmarxdesclist->AppDescNbr -1))

needs to be replaced by

if(descscan < (totalappdescnbr - 1))

The line

WRITE_REG(dmarxdesclist->AppContextDesc, 0);

needs to be added before the return statement.

Cheers, Jan

[Imen.D]

Hello,

Could you please precise in which version of STM32CubeH7 you have found this issue. So, we can verify it.

Regards,

Imen

[JLehm]

Unfortunately we are not able to reliably reconstruct this information, but we are 90% certain that it was STM32Cube H7 V1.3.0.

[Imen.D]

Can you please confirm if that problem is still being faced with the latest version of firmware package STM32CubeH7 v1.4.0 ?

[JLehm · Accepted solution]

I did not test it, but i had a look at the HAL_ETH_BuildRxDescriptors function in version 1.4.0 and i don't see any changes there. So i guess the bug is not fixed yet.

[Imen.D]

Ok, thanks for your reply. We will check this issue internally and come back to you soon with update.

[Imen.D]

Hello,

Sorry for the delay to answer on this request.

The fix is integrated and it will be available in coming release of STM32CubeH7 V1.8.0

Best Regards,

Imen

[Piranha]

Wow, those two small code lines took only one year and four STM32CubeH7 releases... ;)