net: ethernet: ravb: Fix release of refclk

Commit Message

Adam Ford April 21, 2021, 2:05 p.m. UTC

The call to clk_disable_unprepare() can happen before priv is
initialized. This means moving clk_disable_unprepare out of
out_release into a new label.

Fixes: 8ef7adc6beb2 ("net: ethernet: ravb: Enable optional refclk")
Signed-off-by: Adam Ford <[e-mail]>
---
V2:  Rebase on net-next/master, fix fixes tag, change name of label
     from out_unprepare_refclk to out_disable_refclk

Comments

Sergey Shtylyov April 21, 2021, 2:25 p.m. UTC | #1

On 4/21/21 5:05 PM, Adam Ford wrote:

> The call to clk_disable_unprepare() can happen before priv is
> initialized.

   This still doesn't make sense for me...

> This means moving clk_disable_unprepare out of
                                         ^ call
> out_release into a new label.
> 
> Fixes: 8ef7adc6beb2 ("net: ethernet: ravb: Enable optional refclk")
> Signed-off-by: Adam Ford <[e-mail]>

Reviewed-by: Sergei Shtylyov <[e-mail]>


[...]

MBR, Sergei

Adam Ford April 21, 2021, 4:03 p.m. UTC | #2

On Wed, Apr 21, 2021 at 9:25 AM Sergei Shtylyov
<[e-mail]> wrote:
>
> On 4/21/21 5:05 PM, Adam Ford wrote:
>
> > The call to clk_disable_unprepare() can happen before priv is
> > initialized.
>
>    This still doesn't make sense for me...
>
I need an external reference clock enabled by a programmable clock so
I added functionality to turn it on.  [1] When I did it, I was
reminded to disable the clock in the event of an the error condition.
I originally added a call to clk_disable_unprepare(priv->refclk)
under the label called out_release, but a bot responded to me that we
may jump to this error condition before priv is initialized.

This fix is supposed to create a new label so the errors that happen
after the refclk is initialized will get disabled, but any errors that
happen before the clock is initialized will handle errors like they
did before.

Does that help explain things better?

adam

[1] - https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=8ef7adc6beb2ef0bce83513dc9e4505e7b21e8c2

> > This means moving clk_disable_unprepare out of
>                                          ^ call
> > out_release into a new label.
> >
> > Fixes: 8ef7adc6beb2 ("net: ethernet: ravb: Enable optional refclk")
> > Signed-off-by: Adam Ford <[e-mail]>
>
> Reviewed-by: Sergei Shtylyov <[e-mail]>
>
>
> [...]
>
> MBR, Sergei

[e-mail] April 21, 2021, 6:20 p.m. UTC | #3

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Wed, 21 Apr 2021 09:05:05 -0500 you wrote:
> The call to clk_disable_unprepare() can happen before priv is
> initialized. This means moving clk_disable_unprepare out of
> out_release into a new label.
> 
> Fixes: 8ef7adc6beb2 ("net: ethernet: ravb: Enable optional refclk")
> Signed-off-by: Adam Ford <[e-mail]>
> 
> [...]

Here is the summary with links:
  - net: ethernet: ravb: Fix release of refclk
    https://git.kernel.org/netdev/net-next/c/36e69da892f1

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Patch

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 8c84c40ab9a0..9e5dad41cdc9 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2173,7 +2173,7 @@  static int ravb_probe(struct platform_device *pdev)
 	/* Set GTI value */
 	error = ravb_set_gti(ndev);
 	if (error)
-		goto out_release;
+		goto out_disable_refclk;
 
 	/* Request GTI loading */
 	ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);
@@ -2192,7 +2192,7 @@  static int ravb_probe(struct platform_device *pdev)
 			"Cannot allocate desc base address table (size %d bytes)\n",
 			priv->desc_bat_size);
 		error = -ENOMEM;
-		goto out_release;
+		goto out_disable_refclk;
 	}
 	for (q = RAVB_BE; q < DBAT_ENTRY_NUM; q++)
 		priv->desc_bat[q].die_dt = DT_EOS;
@@ -2252,8 +2252,9 @@  static int ravb_probe(struct platform_device *pdev)
 	/* Stop PTP Clock driver */
 	if (chip_id != RCAR_GEN2)
 		ravb_ptp_stop(ndev);
-out_release:
+out_disable_refclk:
 	clk_disable_unprepare(priv->refclk);
+out_release:
 	free_netdev(ndev);
 
 	pm_runtime_put(&pdev->dev);