ERR003744
Chip Errata for the i.MX 6Dual/6Quad and i.MX 6DualPlus/6QuadPlus, Rev. 6.1, 06/2016
114
NXP Semiconductors
Description:
An intdone interrupt must be generated by the AHB Audio DMA when a DMA stop is requested
and a series of AHB transfers is in progress in the AHB bus.
Here, AHB Audio DMA does not generate an interrupt (intdone=1, register AHB_DMA_INT)
after software forces the DMA to stop (stop_dma_transaction, register AHB_DMA_STOP)
between individual AMBA AHB DMA transfers.
For instance, assume that the AHB DMA has performed a series of AHB BUS transfers and its
internal FIFO is full. The AHB DMA starts requesting more AHB BUS transfers only when the
FIFO threshold is reached. In this time period, from the time when the FIFO is full to the time when
AHB DMA starts requesting more transfers, any DMA stop request from software is not registered,
and the AHB Audio DMA does not generate the intdone bit interrupt, although it stops requesting
transactions.
Conditions:
• Setup the system memory with low bandwidth audio (audio sampling rate: 32 kHz, two active
channels)
• Configure the AHB Audio DMA with a data buffer larger than twice the configured FIFO size
• Start an Audio DMA transfer
• Wait for the AHB audio DMA to get bus access and to fill its internal FIFO
• Set stop_dma_transaction bit field (AHB_DMA_STOP register)
Projected Impact:
Medium impact on software driver design. Normally, AHB_DMA_INT will be generated when
DMA finished transferring desired audio data and software driver do not have to stop DMA
transaction by writing AHB_DMA_STOP.
Workarounds:
Poll IH_AHBDMAAUD_STAT0 bit 2 to check when DMA transaction is complete
Proposed Solution:
No fix scheduled
Linux BSP Status:
Software workaround not implemented in Linux BSP. Functionality or mode of operation in which
the erratum may manifest itself is not used.
ERR003744
HDMI: 9000446457—Audio DMA does not generate an interrupt after
software stops DMA transaction
