2019-11-18 12:22:07

by Chuhong Yuan

Subject: [PATCH net v3] net: fec: fix clock count mis-match

pm_runtime_put_autosuspend in probe will call suspend to disable clks
automatically if CONFIG_PM is defined. (If CONFIG_PM is not defined,
its implementation will be empty, then suspend will not be called.)

Therefore, we can call pm_runtime_get_sync to resume it first to enable
clks, which matches the suspend. (Only when CONFIG_PM is defined, otherwise
pm_runtime_get_sync will also be empty, then resume will not be called.)

Then it is fine to disable clks without causing clock count mis-match.

Fixes: c43eab3eddb4 ("net: fec: add missed clk_disable_unprepare in remove")
Signed-off-by: Chuhong Yuan <[email protected]>
---
drivers/net/ethernet/freescale/fec_main.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index a9c386b63581..4bb30761abfc 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3636,6 +3636,11 @@ fec_drv_remove(struct platform_device *pdev)
struct net_device *ndev = platform_get_drvdata(pdev);
struct fec_enet_private *fep = netdev_priv(ndev);
struct device_node *np = pdev->dev.of_node;
+ int ret;
+
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if (ret < 0)
+ return ret;

cancel_work_sync(&fep->tx_timeout_work);
fec_ptp_stop(pdev);
@@ -3643,15 +3648,17 @@ fec_drv_remove(struct platform_device *pdev)
fec_enet_mii_remove(fep);
if (fep->reg_phy)
regulator_disable(fep->reg_phy);
- pm_runtime_put(&pdev->dev);
- pm_runtime_disable(&pdev->dev);
- clk_disable_unprepare(fep->clk_ahb);
- clk_disable_unprepare(fep->clk_ipg);
+
if (of_phy_is_fixed_link(np))
of_phy_deregister_fixed_link(np);
of_node_put(fep->phy_node);
free_netdev(ndev);

+ clk_disable_unprepare(fep->clk_ahb);
+ clk_disable_unprepare(fep->clk_ipg);
+ pm_runtime_put_noidle(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+
return 0;
}

--
2.24.0

2019-11-19 01:51:10

by Andy Duan

Subject: RE: [EXT] [PATCH net v3] net: fec: fix clock count mis-match

From: Chuhong Yuan <[email protected]> Sent: Monday, November 18, 2019 8:18 PM
> pm_runtime_put_autosuspend in probe will call suspend to disable clks
> automatically if CONFIG_PM is defined. (If CONFIG_PM is not defined, its
> implementation will be empty, then suspend will not be called.)

suspend -> runtime suspend
>
> Therefore, we can call pm_runtime_get_sync to resume it first to enable clks,
resume -> runtime resume
> which matches the suspend. (Only when CONFIG_PM is defined, otherwise
suspend -> runtime suspend
> pm_runtime_get_sync will also be empty, then resume will not be called.)
>
> Then it is fine to disable clks without causing clock count mis-match.
>
> Fixes: c43eab3eddb4 ("net: fec: add missed clk_disable_unprepare in
> remove")
> Signed-off-by: Chuhong Yuan <[email protected]>
> ---
> drivers/net/ethernet/freescale/fec_main.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index a9c386b63581..4bb30761abfc 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -3636,6 +3636,11 @@ fec_drv_remove(struct platform_device *pdev)
> struct net_device *ndev = platform_get_drvdata(pdev);
> struct fec_enet_private *fep = netdev_priv(ndev);
> struct device_node *np = pdev->dev.of_node;
> + int ret;
> +
> + ret = pm_runtime_get_sync(&pdev->dev);
> + if (ret < 0)
> + return ret;
>
> cancel_work_sync(&fep->tx_timeout_work);
> fec_ptp_stop(pdev);
> @@ -3643,15 +3648,17 @@ fec_drv_remove(struct platform_device *pdev)
> fec_enet_mii_remove(fep);
> if (fep->reg_phy)
> regulator_disable(fep->reg_phy);
> - pm_runtime_put(&pdev->dev);
> - pm_runtime_disable(&pdev->dev);
> - clk_disable_unprepare(fep->clk_ahb);
> - clk_disable_unprepare(fep->clk_ipg);
> +
> if (of_phy_is_fixed_link(np))
> of_phy_deregister_fixed_link(np);
> of_node_put(fep->phy_node);
> free_netdev(ndev);
>
> + clk_disable_unprepare(fep->clk_ahb);
> + clk_disable_unprepare(fep->clk_ipg);
> + pm_runtime_put_noidle(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> +
> return 0;
> }
>
> --
> 2.24.0

2019-11-19 22:56:48

by David Miller

Subject: Re: [PATCH net v3] net: fec: fix clock count mis-match

From: Chuhong Yuan <[email protected]>
Date: Mon, 18 Nov 2019 20:18:26 +0800

> pm_runtime_put_autosuspend in probe will call suspend to disable clks
> automatically if CONFIG_PM is defined. (If CONFIG_PM is not defined,
> its implementation will be empty, then suspend will not be called.)
>
> Therefore, we can call pm_runtime_get_sync to resume it first to enable
> clks, which matches the suspend. (Only when CONFIG_PM is defined, otherwise
> pm_runtime_get_sync will also be empty, then resume will not be called.)
>
> Then it is fine to disable clks without causing clock count mis-match.
>
> Fixes: c43eab3eddb4 ("net: fec: add missed clk_disable_unprepare in remove")
> Signed-off-by: Chuhong Yuan <[email protected]>

Please fix the commit message typos pointed out by Andy Duan and resubmit,
thank you.