i2c: mux: reg Change ioread endianness for readback

Reading the register (if allowed) after writing is to ensure writing
is completed on a posted bus. The endianness of reading doesn't matter.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/muxes/i2c-mux-reg.c b/drivers/i2c/muxes/i2c-mux-reg.c
index 7913d80..5fbd5bd 100644 (file)
--- a/drivers/i2c/muxes/i2c-mux-reg.c
+++ b/drivers/i2c/muxes/i2c-mux-reg.c
@@ -31,28 +31,28 @@ static int i2c_mux_reg_set(const struct regmux *mux, unsigned int chan_id)
        if (!mux->data.reg)
                return -EINVAL;
 
+       /*
+        * Write to the register, followed by a read to ensure the write is
+        * completed on a "posted" bus, for example PCI or write buffers.
+        * The endianness of reading doesn't matter and the return data
+        * is not used.
+        */
        switch (mux->data.reg_size) {
        case 4:
-               if (mux->data.little_endian) {
+               if (mux->data.little_endian)
                        iowrite32(chan_id, mux->data.reg);
-                       if (!mux->data.write_only)
-                               ioread32(mux->data.reg);
-               } else {
+               else
                        iowrite32be(chan_id, mux->data.reg);
-                       if (!mux->data.write_only)
-                               ioread32(mux->data.reg);
-               }
+               if (!mux->data.write_only)
+                       ioread32(mux->data.reg);
                break;
        case 2:
-               if (mux->data.little_endian) {
+               if (mux->data.little_endian)
                        iowrite16(chan_id, mux->data.reg);
-                       if (!mux->data.write_only)
-                               ioread16(mux->data.reg);
-               } else {
+               else
                        iowrite16be(chan_id, mux->data.reg);
-                       if (!mux->data.write_only)
-                               ioread16be(mux->data.reg);
-               }
+               if (!mux->data.write_only)
+                       ioread16(mux->data.reg);
                break;
        case 1:
                iowrite8(chan_id, mux->data.reg);