3.3-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dan Williams <[email protected]> commit 49b532f96fda23663f8be35593d1c1372c0f91e0 upstream. This reverts commit 448ac154c957c4580531fa0c8f2045816fe2f0e7. The semantic of UPF_IIR_ONCE is only guaranteed to workaround the race condition in the kt serial's iir register if the only source of interrupts is THRE (fifo-empty) events. An modem status event at the wrong time can again cause an iir read to drop the 'empty' status leading to a hang. So, revert this in preparation for using the existing "I don't trust my iir register" workaround in the 8250 core (UART_BUG_THRE). Acked-by: Alan Cox <[email protected]> Cc: Sudhakar Mamillapalli <[email protected]> Reported-by: Nhan H Mai <[email protected]> Signed-off-by: Dan Williams <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/tty/serial/8250/8250.c | 4 +--- drivers/tty/serial/8250/8250_pci.c | 17 +---------------- include/linux/serial_core.h | 1 - 3 files changed, 2 insertions(+), 20 deletions(-) --- a/drivers/tty/serial/8250/8250.c +++ b/drivers/tty/serial/8250/8250.c @@ -1592,13 +1592,11 @@ static irqreturn_t serial8250_interrupt( do { struct uart_8250_port *up; struct uart_port *port; - bool skip; up = list_entry(l, struct uart_8250_port, list); port = &up->port; - skip = pass_counter && up->port.flags & UPF_IIR_ONCE; - if (!skip && port->handle_irq(port)) { + if (port->handle_irq(port)) { handled = 1; end = NULL; } else if (end == NULL) --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1092,14 +1092,6 @@ static int skip_tx_en_setup(struct seria return pci_default_setup(priv, board, port, idx); } -static int kt_serial_setup(struct serial_private *priv, - const struct pciserial_board *board, - struct uart_port *port, int idx) -{ - port->flags |= UPF_IIR_ONCE; - return skip_tx_en_setup(priv, board, port, idx); -} - static int pci_eg20t_init(struct pci_dev *dev) { #if defined(CONFIG_SERIAL_PCH_UART) || defined(CONFIG_SERIAL_PCH_UART_MODULE) @@ -1118,6 +1110,7 @@ pci_xr17c154_setup(struct serial_private return pci_default_setup(priv, board, port, idx); } +/* This should be in linux/pci_ids.h */ #define PCI_VENDOR_ID_SBSMODULARIO 0x124B #define PCI_SUBVENDOR_ID_SBSMODULARIO 0x124B #define PCI_DEVICE_ID_OCTPRO 0x0001 @@ -1147,7 +1140,6 @@ pci_xr17c154_setup(struct serial_private #define PCI_DEVICE_ID_OXSEMI_16PCI958 0x9538 #define PCIE_DEVICE_ID_NEO_2_OX_IBM 0x00F6 #define PCI_DEVICE_ID_PLX_CRONYX_OMEGA 0xc001 -#define PCI_DEVICE_ID_INTEL_PATSBURG_KT 0x1d3d /* Unknown vendors/cards - this should not be in linux/pci_ids.h */ #define PCI_SUBDEVICE_ID_UNKNOWN_0x1584 0x1584 @@ -1232,13 +1224,6 @@ static struct pci_serial_quirk pci_seria .subdevice = PCI_ANY_ID, .setup = ce4100_serial_setup, }, - { - .vendor = PCI_VENDOR_ID_INTEL, - .device = PCI_DEVICE_ID_INTEL_PATSBURG_KT, - .subvendor = PCI_ANY_ID, - .subdevice = PCI_ANY_ID, - .setup = kt_serial_setup, - }, /* * ITE */ --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -355,7 +355,6 @@ struct uart_port { #define UPF_CONS_FLOW ((__force upf_t) (1 << 23)) #define UPF_SHARE_IRQ ((__force upf_t) (1 << 24)) #define UPF_EXAR_EFR ((__force upf_t) (1 << 25)) -#define UPF_IIR_ONCE ((__force upf_t) (1 << 26)) /* The exact UART type is known and should not be probed. */ #define UPF_FIXED_TYPE ((__force upf_t) (1 << 27)) #define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28)) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
