intel_scu_ipc: move error check out of the loop

This is small performance optimization of the busy_loop().

While here, use BIT() macro instead of plain integers when check the status.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 8938c31be44790967fccb7b2d71935f961c68d44..e6430a3454cffebadf68c3a6b87d7d1f0369a65f 100644 (file)
--- a/drivers/platform/x86/intel_scu_ipc.c
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -176,21 +176,21 @@ static inline u32 ipc_data_readl(u32 offset) /* Read ipc u32 data */
 /* Wait till scu status is busy */
 static inline int busy_loop(void)
 {
-       u32 status = 0;
-       u32 loop_count = 0;
+       u32 status = ipc_read_status();
+       u32 loop_count = 100000;
 
-       status = ipc_read_status();
-       while (status & 1) {
+       /* break if scu doesn't reset busy bit after huge retry */
+       while ((status & BIT(0)) && --loop_count) {
                udelay(1); /* scu processing time is in few u secods */
                status = ipc_read_status();
-               loop_count++;
-               /* break if scu doesn't reset busy bit after huge retry */
-               if (loop_count > 100000) {
-                       dev_err(&ipcdev.pdev->dev, "IPC timed out");
-                       return -ETIMEDOUT;
-               }
        }
-       if ((status >> 1) & 1)
+
+       if (status & BIT(0)) {
+               dev_err(&ipcdev.pdev->dev, "IPC timed out");
+               return -ETIMEDOUT;
+       }
+
+       if (status & BIT(1))
                return -EIO;
 
        return 0;
@@ -208,8 +208,7 @@ static inline int ipc_wait_for_interrupt(void)
        }
 
        status = ipc_read_status();
-
-       if ((status >> 1) & 1)
+       if (status & BIT(1))
                return -EIO;
 
        return 0;