tty: serial: linflexuart: UART support for FIFO with DMA
commit 96e078dfd6537ad3069ef0ea2f708e2836cc6754 from https://github.com/nxp-auto-linux/linux Add Linflex FIFO support with DMA to avoid generating one interrupt per character and losing characters while copy-paste. If the edma is not enabled, the Linflex driver will fallback to BufferMode. tty: serial: linflexuart: Fix memory corruption in fsl_linflexuart The memory is corrupted when UART is using DMA. The issue is easily seen when the SLUB allocator is used and that affects the RT patch. The memory is corrupted in linflex_dma_tx_complete, when calling async_tx_ack because the function modifies the memory freed in fsl_edma_free_desc. DMA_CTRL_ACK, if cleared, the descriptor cannot be reused by provider until the client sends ack, i.e. has a chance to establish any dependency chains. In our case, we don't need the descriptor after completion so we can set the flag in dmaengine_prep_slave_single. Issue: ALB-57 Issue: ALB-448 Issue: ALB-9101 Signed-off-by:Stoica Cosmin-Stefan <cosmin.stoica@nxp.com> Signed-off-by:
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