Re: [PATCHv2 1/2] drivers: net: davinci_mdio: remove busy loop on wait user access
flat view
From: Grygorii Strashko <grygorii.strashko@ti.com>
Date: 2017-08-10 16:24:52
Also in:
linux-omap
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 <redacted>
yep. cover letter is good to have. Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
quoted hunk ↗ jump to hunk
--- 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