From: Andy Shevchenko <andriy.shevche...@linux.intel.com> Backport: - Upstream-Status: Pending. [https://bitbucket.org/andy-shev/linux/commits/5fe86674840c6773d09943a78a5f7f3bf2420ffd?at=master]
When any 8250 based driver sets up DMA and has UART_CAP_RPM capability enabled the device is left powered on after transfer is done. We need to schedule a device suspend operation when DMA completes the transfer. The patch is based on the work done by the reporter. Reported-by: Huiquan Zhong <huiquan.zh...@intel.com> Signed-off-by: Andy Shevchenko <andriy.shevche...@linux.intel.com> --- drivers/tty/serial/8250/8250_dma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c index 78259d3..d9b93d1 100644 --- a/drivers/tty/serial/8250/8250_dma.c +++ b/drivers/tty/serial/8250/8250_dma.c @@ -72,10 +72,15 @@ int serial8250_tx_dma(struct uart_8250_port *p) struct dma_async_tx_descriptor *desc; int ret; - if (uart_tx_stopped(&p->port) || dma->tx_running || - uart_circ_empty(xmit)) + if (dma->tx_running) return 0; + if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) { + /* We have been called from __dma_tx_complete() */ + serial8250_rpm_put_tx(p); + return 0; + } + dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); desc = dmaengine_prep_slave_single(dma->txchan, -- 1.9.1 -- _______________________________________________ linux-yocto mailing list linux-yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/linux-yocto