diff options
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 55dc00dd0e5..d984a97043b 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -322,7 +322,22 @@ static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port * .src_maxburst = uap->fifosize >> 2, .device_fc = false, }; + struct dma_slave_caps caps; + /* + * Some DMA controllers provide information on their capabilities. + * If the controller does, check for suitable residue processing + * otherwise assime all is well. + */ + if (0 == dma_get_slave_caps(chan, &caps)) { + if (caps.residue_granularity == + DMA_RESIDUE_GRANULARITY_DESCRIPTOR) { + dma_release_channel(chan); + dev_info(uap->port.dev, + "RX DMA disabled - no residue processing\n"); + return; + } + } dmaengine_slave_config(chan, &rx_conf); uap->dmarx.chan = chan; |