[PATCHv3 0/2] davinci_mdio: remove busy loop on wait user access

[PATCHv3 0/2] davinci_mdio: remove busy loop on wait user access

[Max Uvarov]

v3: no code change, just added cover letter

First patch fixes cpu load on polling busy mdio line.
Second patch just prints which mdio frequency was configured.

Max Uvarov (2):
  drivers: net: davinci_mdio: remove busy loop on wait user access
  drivers: net: davinci_mdio: print bus frequency

 drivers/net/ethernet/ti/davinci_mdio.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

-- 
2.5.0

[PATCHv3 1/2] drivers: net: davinci_mdio: remove busy loop on wait user access

[Max Uvarov]

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@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
 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(&regs->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
-- 
2.5.0

[PATCHv3 2/2] drivers: net: davinci_mdio: print bus frequency

[Max Uvarov]

Frequency can be adjusted in DT it make sense to
print current used value on driver init.

Signed-off-by: Max Uvarov <muvarov@gmail.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
 drivers/net/ethernet/ti/davinci_mdio.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index 611e7cc..3c33f45 100644
--- a/drivers/net/ethernet/ti/davinci_mdio.c
+++ b/drivers/net/ethernet/ti/davinci_mdio.c
@@ -159,8 +159,10 @@ static int davinci_mdio_reset(struct mii_bus *bus)
 
 	/* dump hardware version info */
 	ver = __raw_readl(&data->regs->version);
-	dev_info(data->dev, "davinci mdio revision %d.%d\n",
-		 (ver >> 8) & 0xff, ver & 0xff);
+	dev_info(data->dev,
+		 "davinci mdio revision %d.%d, bus freq %ld\n",
+		 (ver >> 8) & 0xff, ver & 0xff,
+		 data->pdata.bus_freq);
 
 	if (data->skip_scan)
 		goto done;
-- 
2.5.0