Deprecate wait() in favour of acquire(), try_acquire(),
try_acquire_for() and try_acquire_until().
Brings Semaphore more into line with CMSIS-RTOS 2 (which uses "acquire"),
itself (as it has "release"), and other classes having "try", "try for"
and "try until".
Also steps away from vague "wait" term - the primary operation here is
to acquire the semaphore, and this will of course sleep.
Since commit 12c6b1bd8, the i.MX RT1050 has effectively had its data
cache disabled, as the SDRAM was marked Shareable; for the Cortex-M7,
shareable memory is not cached.
This was done to make the Ethernet driver work without any cache
maintenance code. This commit adds cache maintenance and memory barriers
to the Ethernet driver, and removes the Shareable attribute from the
SDRAM, so the data cache is used again.
Cache code in the base fsl_enet.c driver has not been activated - the
bulk of it is in higher-level Read and Write calls that we're not using,
and there is one flawed invalidate in its initialisation. Instead
imx_emac.cpp takes full cache responsibility.
This commit also marks the SDRAM as read/write-allocate. As the
Cortex-M7 has its "Dynamic read allocate mode" to automatically switch
back to read-allocate in cases where write allocate is working poorly
(eg large memset), this should result in a performance boost with no
downside.
Activating write-allocate is also an attempt to provoke any flaws in
cache maintenance - the Ethernet transmit buffers for example will be
more likely to have a little data in the cache that needs cleaning.
When all TX descriptors were reserved in a row so that TX buffer
reclaim interrupt did not happen during reservation sequence, after
the interrupt occurred, TX buffer reclaim did no longer free buffers.
This happened because when all descriptors were in use, last free
index pointed to consumed index.
Subtract 4 from the received packet length - the buffer contains the
CRC, which we shouldn't pass up.
Ensure we allocate receive buffers of a size corresponding to the
rounded-up size we tell the hardware - the hardware was overrunning the
allocation by a couple of bytes.
Caleb Szalacinski
Mahesh Mahadevan
Kevin Bracey
Seppo Takalo
Jimmy Brisson
Martin Kojtal
Mika Leppänen