From: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> commit 1bfcbe5805d0cfc83c3544dcd01e0a282c1f6790 upstream. If the platform doesn't use DMA device filter (as is the case with Elkhart Lake), whole lpss8250_dma_setup() setup is skipped. This results in skipping also *_maxburst setup which is undesirable. Refactor lpss8250_dma_setup() to configure DMA even if filter is not setup. Cc: stable <stable@xxxxxxxxxx> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20221108121952.5497-3-ilpo.jarvinen@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/8250/8250_lpss.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -278,8 +278,13 @@ static int lpss8250_dma_setup(struct lps struct dw_dma_slave *rx_param, *tx_param; struct device *dev = port->port.dev; - if (!lpss->dma_param.dma_dev) + if (!lpss->dma_param.dma_dev) { + dma = port->dma; + if (dma) + goto out_configuration_only; + return 0; + } rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL); if (!rx_param) @@ -290,16 +295,18 @@ static int lpss8250_dma_setup(struct lps return -ENOMEM; *rx_param = lpss->dma_param; - dma->rxconf.src_maxburst = lpss->dma_maxburst; - *tx_param = lpss->dma_param; - dma->txconf.dst_maxburst = lpss->dma_maxburst; dma->fn = lpss8250_dma_filter; dma->rx_param = rx_param; dma->tx_param = tx_param; port->dma = dma; + +out_configuration_only: + dma->rxconf.src_maxburst = lpss->dma_maxburst; + dma->txconf.dst_maxburst = lpss->dma_maxburst; + return 0; }
