serial: 8250_mid: set PCI master only for DMA capable device

There is no need to set PCI bus mastering when device is not doing any DMA. It
includes MSI type of interrupts. Currently only UART on Denverton, which is DMA
capable, might have MSI enabled.

Taking above into account enable bus mastering for Denverton case only.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
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_mid.c b/drivers/tty/serial/8250/8250_mid.c
index 85011c9..ec957cc 100644 (file)
--- a/drivers/tty/serial/8250/8250_mid.c
+++ b/drivers/tty/serial/8250/8250_mid.c
@@ -164,6 +164,8 @@ static int dnv_setup(struct mid8250 *mid, struct uart_port *p)
        unsigned int bar = FL_GET_BASE(mid->board->flags);
        int ret;
 
+       pci_set_master(pdev);
+
        ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
        if (ret < 0)
                return ret;
@@ -289,8 +291,6 @@ static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        if (ret)
                return ret;
 
-       pci_set_master(pdev);
-
        mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
        if (!mid)
                return -ENOMEM;