The MSCC MIIM MDIO driver uses delays to read poll a status register. I
made multiple tests on a Ocelot PCS120 platform which led me to reduce
those delays. The delay in between which the polling function is allowed
to sleep is reduced from 100us to 50us which in almost all cases is a
good value to succeed at the first retry. The overall delay is also
lowered as the prior value was really way to high, 10000us is large
enough.
Signed-off-by: Antoine Tenart <[email protected]>
---
drivers/net/phy/mdio-mscc-miim.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/phy/mdio-mscc-miim.c b/drivers/net/phy/mdio-mscc-miim.c
index badbc99bedd3..0b7544f593fb 100644
--- a/drivers/net/phy/mdio-mscc-miim.c
+++ b/drivers/net/phy/mdio-mscc-miim.c
@@ -44,7 +44,7 @@ static int mscc_miim_wait_ready(struct mii_bus *bus)
u32 val;
readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
- !(val & MSCC_MIIM_STATUS_STAT_BUSY), 100, 250000);
+ !(val & MSCC_MIIM_STATUS_STAT_BUSY), 50, 10000);
if (val & MSCC_MIIM_STATUS_STAT_BUSY)
return -ETIMEDOUT;
--
2.26.2
On 26/05/2020 18:22:53+0200, Antoine T?nart wrote:
> The MSCC MIIM MDIO driver uses delays to read poll a status register. I
> made multiple tests on a Ocelot PCS120 platform which led me to reduce
> those delays. The delay in between which the polling function is allowed
> to sleep is reduced from 100us to 50us which in almost all cases is a
> good value to succeed at the first retry. The overall delay is also
> lowered as the prior value was really way to high, 10000us is large
> enough.
>
> Signed-off-by: Antoine Tenart <[email protected]>
Reviewed-by: Alexandre Belloni <[email protected]>
> ---
> drivers/net/phy/mdio-mscc-miim.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/phy/mdio-mscc-miim.c b/drivers/net/phy/mdio-mscc-miim.c
> index badbc99bedd3..0b7544f593fb 100644
> --- a/drivers/net/phy/mdio-mscc-miim.c
> +++ b/drivers/net/phy/mdio-mscc-miim.c
> @@ -44,7 +44,7 @@ static int mscc_miim_wait_ready(struct mii_bus *bus)
> u32 val;
>
> readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
> - !(val & MSCC_MIIM_STATUS_STAT_BUSY), 100, 250000);
> + !(val & MSCC_MIIM_STATUS_STAT_BUSY), 50, 10000);
> if (val & MSCC_MIIM_STATUS_STAT_BUSY)
> return -ETIMEDOUT;
>
> --
> 2.26.2
>
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
On 5/26/2020 9:22 AM, Antoine Tenart wrote:
> The MSCC MIIM MDIO driver uses delays to read poll a status register. I
> made multiple tests on a Ocelot PCS120 platform which led me to reduce
> those delays. The delay in between which the polling function is allowed
> to sleep is reduced from 100us to 50us which in almost all cases is a
> good value to succeed at the first retry. The overall delay is also
> lowered as the prior value was really way to high, 10000us is large
> enough.
>
> Signed-off-by: Antoine Tenart <[email protected]>
Reviewed-by: Florian Fainelli <[email protected]>
--
Florian