Hi,
On 2/10/23 05:48, Orlando Chamberlain wrote:
> Currently it manually flips the byte order, but we can instead use
> cpu_to_be32(val) for this.
>
> Signed-off-by: Orlando Chamberlain <orlandoch.dev@xxxxxxxxx>
> ---
> drivers/platform/x86/apple-gmux.c | 18 ++----------------
> 1 file changed, 2 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c
> index 9333f82cfa8a..e8cb084cb81f 100644
> --- a/drivers/platform/x86/apple-gmux.c
> +++ b/drivers/platform/x86/apple-gmux.c
> @@ -94,13 +94,7 @@ static u32 gmux_pio_read32(struct apple_gmux_data *gmux_data, int port)
> static void gmux_pio_write32(struct apple_gmux_data *gmux_data, int port,
> u32 val)
> {
> - int i;
> - u8 tmpval;
> -
> - for (i = 0; i < 4; i++) {
> - tmpval = (val >> (i * 8)) & 0xff;
> - outb(tmpval, gmux_data->iostart + port + i);
> - }
> + outl(cpu_to_be32(val), gmux_data->iostart + port);
> }
>
> static int gmux_index_wait_ready(struct apple_gmux_data *gmux_data)
The ioport / indexed-ioport accessed apple_gmux-es likely are (part of?)
LPC bus devices . Looking at the bus level you are now changing 4 io
accesses with a size of 1 byte, to 1 32 bit io-access.
Depending on the decoding hw in the chip this may work fine,
or this may work not at all.
I realized that you have asked for more testing, but most surviving
macbooks from the older apple-gmux era appear to be models without
a discrete GPU (which are often the first thing to break) and thus
without a gmux.
Unless we get a bunch of testers to show up, which I doubt. I would
prefer slightly bigger / less pretty code and not change the functional
behavior of the driver on these older models.
Regards,
Hans
> @@ -177,16 +171,8 @@ static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)
> static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
> u32 val)
> {
> - int i;
> - u8 tmpval;
> -
> mutex_lock(&gmux_data->index_lock);
> -
> - for (i = 0; i < 4; i++) {
> - tmpval = (val >> (i * 8)) & 0xff;
> - outb(tmpval, gmux_data->iostart + GMUX_PORT_VALUE + i);
> - }
> -
> + outl(cpu_to_be32(val), gmux_data->iostart + GMUX_PORT_VALUE);
> gmux_index_wait_ready(gmux_data);
> outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
> gmux_index_wait_complete(gmux_data);
