Fix ethernet memory handling issues on CM3DS

[kapi90]

Signed-off-by: Bence Kaposzta bence.kaposzta@arm.com

Description (required)

There had been a memory leak in the SMSC9220's EMAC driver that is fixed in this patch.

Summary of change (What the change is for and why)

Documentation (Details of any document updates required)

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Pull request type (required)

[x] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results (required)

[] No Tests required for this change (E.g docs only update)
[x] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

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Reviewers (optional)

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Release Notes (required for feature/major PRs)

Summary of changes

Impact of changes

Migration actions required

[kjbracey]

I can't actually see a leak being fixed here. The length is now being set correctly on received packets, rather than just indicating "full size", but doesn't seem like that would have caused a leak. Can you clarify?

[ciarmcom]

@kapi90, thank you for your changes.
@ashok-rao @ARMmbed/mbed-os-ipcore @ARMmbed/mbed-os-maintainers please review.

[kapi90]

I can't actually see a leak being fixed here. The length is now being set correctly on received packets, rather than just indicating "full size", but doesn't seem like that would have caused a leak. Can you clarify?

This is an older patch that has been pushed back due to priority changes since March, it seems that most of the memory leak related changes has been applied previously (our local repo must have got out of sync somewhere). Therefore, please consider this as a minor follow up.

[0xc0170]

Started first CI

[mbed-ci]

Test run: FAILED

Summary: 3 of 4 test jobs failed
Build number : 1
Build artifacts

Failed test jobs:

• jenkins-ci/mbed-os-ci_build-IAR
• jenkins-ci/mbed-os-ci_build-GCC_ARM
• jenkins-ci/mbed-os-ci_build-ARM

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 2
Build artifacts