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* [PATCH 3/5] tc35815: Increase timeout for mdio
@ 2009-08-06 14:41 Atsushi Nemoto
  2009-08-06 20:16 ` David Miller
  0 siblings, 1 reply; 2+ messages in thread
From: Atsushi Nemoto @ 2009-08-06 14:41 UTC (permalink / raw)
  To: netdev; +Cc: David Miller, Ralf Roesch

The current timeout value is too short for very high-load condition
which jiffies might jump up in busy-loop.
Also add minimum delay before checking completion of MDIO.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
 drivers/net/tc35815.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/tc35815.c b/drivers/net/tc35815.c
index 801d201..1adb150 100644
--- a/drivers/net/tc35815.c
+++ b/drivers/net/tc35815.c
@@ -594,9 +594,10 @@ static int tc_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
 	struct net_device *dev = bus->priv;
 	struct tc35815_regs __iomem *tr =
 		(struct tc35815_regs __iomem *)dev->base_addr;
-	unsigned long timeout = jiffies + 10;
+	unsigned long timeout = jiffies + HZ;
 
 	tc_writel(MD_CA_Busy | (mii_id << 5) | (regnum & 0x1f), &tr->MD_CA);
+	udelay(12); /* it takes 32 x 400ns at least */
 	while (tc_readl(&tr->MD_CA) & MD_CA_Busy) {
 		if (time_after(jiffies, timeout))
 			return -EIO;
@@ -610,11 +611,12 @@ static int tc_mdio_write(struct mii_bus *bus, int mii_id, int regnum, u16 val)
 	struct net_device *dev = bus->priv;
 	struct tc35815_regs __iomem *tr =
 		(struct tc35815_regs __iomem *)dev->base_addr;
-	unsigned long timeout = jiffies + 10;
+	unsigned long timeout = jiffies + HZ;
 
 	tc_writel(val, &tr->MD_Data);
 	tc_writel(MD_CA_Busy | MD_CA_Wr | (mii_id << 5) | (regnum & 0x1f),
 		  &tr->MD_CA);
+	udelay(12); /* it takes 32 x 400ns at least */
 	while (tc_readl(&tr->MD_CA) & MD_CA_Busy) {
 		if (time_after(jiffies, timeout))
 			return -EIO;
-- 
1.5.6.5


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH 3/5] tc35815: Increase timeout for mdio
  2009-08-06 14:41 [PATCH 3/5] tc35815: Increase timeout for mdio Atsushi Nemoto
@ 2009-08-06 20:16 ` David Miller
  0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2009-08-06 20:16 UTC (permalink / raw)
  To: anemo; +Cc: netdev, ralf.roesch

From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Date: Thu,  6 Aug 2009 23:41:47 +0900

> The current timeout value is too short for very high-load condition
> which jiffies might jump up in busy-loop.
> Also add minimum delay before checking completion of MDIO.
> 
> Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>

Applied to net-next-2.6

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2009-08-06 14:41 [PATCH 3/5] tc35815: Increase timeout for mdio Atsushi Nemoto
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