[PATCH 06/10] drivers: PL011: replace UART_MIS reading with _RIS & _IMSC
Andre Przywara
andre.przywara at arm.com
Fri Jan 16 09:23:02 PST 2015
The PL011 register UART_MIS is actually a bitwise AND of the
UART_RIS and the UART_MISC register.
Since the SBSA UART does not include the _MIS register, use the
two separate registers to get the same behaviour. Since we are
inside the spinlock and we read the _IMSC register only once, there
should be no race issue.
Signed-off-by: Andre Przywara <andre.przywara at arm.com>
---
drivers/tty/serial/amba-pl011.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index e484551..e6c2746 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1350,11 +1350,13 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
struct uart_amba_port *uap = dev_id;
unsigned long flags;
unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
+ u16 imsc;
int handled = 0;
unsigned int dummy_read;
spin_lock_irqsave(&uap->port.lock, flags);
- status = readw(uap->port.membase + UART011_MIS);
+ imsc = readw(uap->port.membase + UART011_IMSC);
+ status = readw(uap->port.membase + UART011_RIS) & imsc;
if (status) {
do {
if (uap->vendor->cts_event_workaround) {
@@ -1391,7 +1393,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
if (pass_counter-- == 0)
break;
- status = readw(uap->port.membase + UART011_MIS);
+ status = readw(uap->port.membase + UART011_RIS) & imsc;
} while (status != 0);
handled = 1;
}
--
1.7.9.5
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