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| author | Dan Williams <dan.j.williams@intel.com> | 2012-04-06 20:49:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-04-09 19:34:52 +0200 |
| commit | 49b532f96fda23663f8be35593d1c1372c0f91e0 (patch) | |
| tree | 778aacfa431d612f03a136847a0ebe84a9ffe82a /drivers/tty/serial/8250/8250.c | |
| parent | Revert "serial/8250_pci: init-quirk msi support for kt serial controller" (diff) | |
| download | linux-49b532f96fda23663f8be35593d1c1372c0f91e0.tar.xz linux-49b532f96fda23663f8be35593d1c1372c0f91e0.zip | |
Revert "serial/8250_pci: setup-quirk workaround for the kt serial controller"
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).
[stable: 3.3.x]
Cc: stable <stable@vger.kernel.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: Sudhakar Mamillapalli <sudhakar@fb.com>
Reported-by: Nhan H Mai <nhan.h.mai@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/8250/8250.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c index 5b149b466ec8..56492d208a7a 100644 --- a/drivers/tty/serial/8250/8250.c +++ b/drivers/tty/serial/8250/8250.c @@ -1572,13 +1572,11 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id) 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) |