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@xxxxxxxxxxxxxxx>
---
drivers/platform/x86/intel_scu_ipc.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 8938c31..e6430a3 100644
--- 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;
--
2.1.4
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