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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>
This commit is contained in:
Andy Shevchenko 2015-01-21 21:38:10 +02:00 committed by Darren Hart
parent 7c2e3c7476
commit f0295a36dc
1 changed files with 12 additions and 13 deletions
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21
drivers/platform/x86/intel_scu_ipc.c
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@ -176,21 +176,21 @@ static inline u32 ipc_data_readl(u32 offset) /* Read ipc u32 data */
/* Wait till scu status is busy */ /* Wait till scu status is busy */
static inline int busy_loop(void) static inline int busy_loop(void)
{ {
u32 status = 0; u32 status = ipc_read_status();
u32 loop_count = 0; u32 loop_count = 100000;
status = ipc_read_status(); /* break if scu doesn't reset busy bit after huge retry */
while (status & 1) { while ((status & BIT(0)) && --loop_count) {
udelay(1); /* scu processing time is in few u secods */ udelay(1); /* scu processing time is in few u secods */
status = ipc_read_status(); status = ipc_read_status();
loop_count++; }
/* break if scu doesn't reset busy bit after huge retry */
if (loop_count > 100000) { if (status & BIT(0)) {
dev_err(&ipcdev.pdev->dev, "IPC timed out"); dev_err(&ipcdev.pdev->dev, "IPC timed out");
return -ETIMEDOUT; return -ETIMEDOUT;
} }
}
if ((status >> 1) & 1) if (status & BIT(1))
return -EIO; return -EIO;
return 0; return 0;
@ -208,8 +208,7 @@ static inline int ipc_wait_for_interrupt(void)
} }
status = ipc_read_status(); status = ipc_read_status();
if (status & BIT(1))
if ((status >> 1) & 1)
return -EIO; return -EIO;
return 0; return 0;