With TCD set to loop, there is a window where the
DMA has raised Done, but not reloaded the TCD, resetting
count and clearing Done.
In this window imxrt_dmach_getcount could then return 0.
Resulting in imxrt_dma_nextrx returning RXDMA_BUFFER_SIZE.
Which is not a valid index in the FIFO.
Since the count will be set to RXDMA_BUFFER_SIZE. When the DMA
engine completes the TCD reload. The imxrt_dma_nextrx would
return 0. Therefore:
(RXDMA_BUFFER_SIZE - dmaresidual) % RXDMA_BUFFER_SIZE
accomplishes this.
With TCD set to loop, there is a window where the
DMA has raised Done, but not reloaded the TCD, resetting
count and clearing Done.
In this window imxrt_dmach_getcount could then return 0.
Resulting in imxrt_dma_nextrx returning RXDMA_BUFFER_SIZE.
Which is not a valid index in the FIFO.
Since the count will be set to RXDMA_BUFFER_SIZE. When the DMA
engine completes the TCD reload. The imxrt_dma_nextrx would
return 0. Therefore:
(RXDMA_BUFFER_SIZE - dmaresidual) % RXDMA_BUFFER_SIZE
accomplishes this.
With DMA enabled on some I2C channels but not all
the Non DMA channels were failing.
The cause was condition the status with only the enabled
interrupts on non DMA chennels. This conditioning needs
to only happen in DMA enabled channels
With DMA enabled on some I2C channels but not all
the Non DMA channels were failing.
The cause was condition the status with only the enabled
interrupts on non DMA chennels. This conditioning needs
to only happen in DMA enabled channels
With DMA enabled on some I2C channels but not all
the Non DMA channels were failing.
The cause was condition the status with only the enabled
interrupts on non DMA chennels. This conditioning needs
to only happen in DMA enabled channels
The DMA can bring in more rx data, than the number of
DMA completions call backs. The call back happen on
idle, 1/2 and full events. But in between these events
the DMA can write more data to the buffers memory that
need to be brought in to the cache. (invalidate)
We do the invalidate on the reads from the fifo memory
if the the DMA as commited since the last read.
The BIT macro is widely used in NuttX,
and to achieve a unified strategy,
we have placed the implementation of the BIT macro
in bits.h to simplify code implementation.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
When we build NuttX on macOS, it shows many `sed` messages (and the build still completes successfully):
```text
$ tools/configure.sh pinephone:nsh
$ make
sed: illegal option -- r
```
This is due to the Makefiles executing `sed -r` which is not a valid option on macOS.
This PR proposes to change `sed -r` to `sed -E` because:
- `sed -E` on macOS is equivalent to `sed -r` on Linux
- `sed -E` and `sed -r` are aliases according to the GNU `sed` Manual
- `sed -E` is already used in nuttx_add_romfs.cmake, nuttx_add_symtab.cmake and process_config.sh
stm32_ifdown() holds critical section when calling stm32_ethreset().
That function used to call up_mdelay(10) while waiting for the ethernet
peripheral reset to complete. This resulted in excessively long
critical section time with interrupts disabled.
The actual expected delay is a few clock ticks of the 50 MHz clock domain.
This commit changes polling interval to 1us and maximum to 10us.
