Hi Ilpo,
On 30/12/22 12:46, Ilpo Järvinen wrote:
As unmapped registers are at the tail of the array, the ARRAY_SIZE()
condition will catch them just fine. No need to define special
value for them.
True but fragile example...
Also, let the compiler to calculate the size of the array instead of
providing it manually.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_rt288x.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_rt288x.c b/drivers/tty/serial/8250/8250_rt288x.c
index 3015afb99722..da8be9a802c1 100644
--- a/drivers/tty/serial/8250/8250_rt288x.c
+++ b/drivers/tty/serial/8250/8250_rt288x.c
@@ -14,10 +14,8 @@
#define RT288X_DL 0x28
-#define UART_REG_UNMAPPED -1
-static const s8 au_io_out_map[8] = {
+static const s8 au_io_out_map[] = {
[UART_TX] = 1,
[UART_IER] = 2,
[UART_FCR] = 4,
[UART_LCR] = 5,
[UART_MCR] = 6,
- [UART_LSR] = UART_REG_UNMAPPED,
- [UART_MSR] = UART_REG_UNMAPPED,
- [UART_SCR] = UART_REG_UNMAPPED,
If someone were to re-add an unlikely single
[UART_SCR] = 42,
The array will also contain these hidden entries:
[UART_LSR] = 0,
[UART_MSR] = 0,
And these 2 registers end mapped.
};
Trying to 'optimize' array size when the array is index-initialized
can be bug-prone.
static unsigned int au_serial_in(struct uart_port *p, int offset)
@@ -44,8 +38,7 @@ static unsigned int au_serial_in(struct uart_port *p, int offset)
if (offset >= ARRAY_SIZE(au_io_in_map))
return UINT_MAX;
offset = au_io_in_map[offset];
- if (offset == UART_REG_UNMAPPED)
- return UINT_MAX;
+
return __raw_readl(p->membase + (offset << p->regshift));
}
Regards,
Phil.
