On 08/10/2017 02:47 AM, Max Uvarov wrote:
Polling 14 mdio devices on single mdio bus eats 30% of 1Ghz cpu time
due to busy loop in wait(). Add small delay to relax cpu.
Signed-off-by: Max Uvarov <muvarov@xxxxxxxxx>
yep. cover letter is good to have.
Reviewed-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
v2: fix spelling in commit description.
drivers/net/ethernet/ti/davinci_mdio.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index 33df340..611e7cc 100644
--- a/drivers/net/ethernet/ti/davinci_mdio.c
+++ b/drivers/net/ethernet/ti/davinci_mdio.c
@@ -198,8 +198,10 @@ static inline int wait_for_user_access(struct davinci_mdio_data *data)
return 0;
reg = __raw_readl(®s->control);
- if ((reg & CONTROL_IDLE) == 0)
+ if ((reg & CONTROL_IDLE) == 0) {
+ usleep_range(100, 200);
continue;
+ }
/*
* An emac soft_reset may have clobbered the mdio controller's
--
regards,
-grygorii
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