diff options
| author | Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> | 2019-08-12 13:21:52 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-04 12:43:55 +0200 |
| commit | 8428413b1d14fc880b805c98f571169e7f1ac369 (patch) | |
| tree | f9d510b4402769bec0a2be9137f687a6d36fec82 /drivers/tty | |
| parent | 68e26a8d224f022cf7ec6ebb319a88ad29eb46a4 (diff) | |
serial: 8250_pci: Implement MSI(-X) support
There may be setups, where legacy interrupts are not available. This is
the caese, e.g., when Linux runs as guest (aka. non-root cell) of the
partitioning hypervisor Jailhouse. There, only MSI(-X) interrupts are
available for guests.
But the 8250_pci driver currently only supports legacy ints. So let's
enable MSI(-X) interrupts.
Nevertheless, this needs to handled with care: while many 8250 devices
actually claim to support MSI(-X) interrupts it should not be enabled be
default. I had at least one device in my hands with broken MSI
implementation.
So better introduce a whitelist with devices that are known to support
MSI(-X) interrupts. I tested all devices mentioned in the patch.
Signed-off-by: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de>
Link: https://lore.kernel.org/r/20190812112152.693622-1-ralf.ramsauer@oth-regensburg.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_pci.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 83e21b65d57b..6adbadd6a56a 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -58,6 +58,16 @@ struct serial_private { int line[0]; }; +static const struct pci_device_id pci_use_msi[] = { + { PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9900, + 0xA000, 0x1000) }, + { PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9912, + 0xA000, 0x1000) }, + { PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9922, + 0xA000, 0x1000) }, + { } +}; + static int pci_default_setup(struct serial_private*, const struct pciserial_board*, struct uart_8250_port *, int); @@ -4155,7 +4165,22 @@ pciserial_init_ports(struct pci_dev *dev, const struct pciserial_board *board) memset(&uart, 0, sizeof(uart)); uart.port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ; uart.port.uartclk = board->base_baud * 16; - uart.port.irq = get_pci_irq(dev, board); + + if (pci_match_id(pci_use_msi, dev)) { + dev_dbg(&dev->dev, "Using MSI(-X) interrupts\n"); + pci_set_master(dev); + rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_ALL_TYPES); + } else { + dev_dbg(&dev->dev, "Using legacy interrupts\n"); + rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY); + } + if (rc < 0) { + kfree(priv); + priv = ERR_PTR(rc); + goto err_deinit; + } + + uart.port.irq = pci_irq_vector(dev, 0); uart.port.dev = &dev->dev; for (i = 0; i < nr_ports; i++) { |