[PATCH] Perle multimodem card (PCI-RAS) detection
Get the Perle quad-modem PCI card (PCI-RAS4) detected by serial driver. It
may also get the PCI-RAS8 running, but can't guarantee as I didn't had one for
testing.
Signed-off-by: Thomas Hoehn <thomas.hoehn@avocent.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 5261f0a..2964ca9 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -920,12 +920,16 @@
#ifdef __i386__
outb(0xff, 0x080);
#endif
- scratch2 = serial_inp(up, UART_IER);
+ /*
+ * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
+ * 16C754B) allow only to modify them if an EFR bit is set.
+ */
+ scratch2 = serial_inp(up, UART_IER) & 0x0f;
serial_outp(up, UART_IER, 0x0F);
#ifdef __i386__
outb(0, 0x080);
#endif
- scratch3 = serial_inp(up, UART_IER);
+ scratch3 = serial_inp(up, UART_IER) & 0x0f;
serial_outp(up, UART_IER, scratch);
if (scratch2 != 0 || scratch3 != 0x0F) {
/*