serial: 8250_lpss: set PCI master only for private DMA

There is no need to set PCI bus mastering when device is not doing any DMA.
Though on Intel Quark DMA is a part of UART IP and thus shares same device in
Linux kernel.

Enable bus mastering only for Quark case.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index 886fcf3..353c90e 100644 (file)
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -183,6 +183,8 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
        if (ret)
                return;
 
+       pci_set_master(pdev);
+
        /* Special DMA address for UART */
        dma->rx_dma_addr = 0xfffff000;
        dma->tx_dma_addr = 0xfffff000;
@@ -280,8 +282,6 @@ static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        if (ret)
                return ret;
 
-       pci_set_master(pdev);
-
        lpss = devm_kzalloc(&pdev->dev, sizeof(*lpss), GFP_KERNEL);
        if (!lpss)
                return -ENOMEM;