2023-11-22 17:00:35

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 02/13] net: ravb: Use pm_runtime_resume_and_get()

From: Claudiu Beznea <[email protected]>

pm_runtime_get_sync() may return with error. In case it returns with error
dev->power.usage_count needs to be decremented. pm_runtime_resume_and_get()
takes care of this. Thus use it.

Along with this pm_runtime_resume_and_get() and reset_control_deassert()
were moved before alloc_etherdev_mqs() to simplify the error path.

Also, in case pm_runtime_resume_and_get() returns error the reset signal
is deasserted and runtime PM is disabled (by jumping to the proper
error handling label).

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Claudiu Beznea <[email protected]>
---
drivers/net/ethernet/renesas/ravb_main.c | 28 +++++++++++++-----------
1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 342978bdbd7e..0486add302b3 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2635,25 +2635,26 @@ static int ravb_probe(struct platform_device *pdev)
return dev_err_probe(&pdev->dev, PTR_ERR(rstc),
"failed to get cpg reset\n");

+ error = reset_control_deassert(rstc);
+ if (error)
+ return error;
+
+ pm_runtime_enable(&pdev->dev);
+ error = pm_runtime_resume_and_get(&pdev->dev);
+ if (error < 0)
+ goto pm_runtime_disable;
+
ndev = alloc_etherdev_mqs(sizeof(struct ravb_private),
NUM_TX_QUEUE, NUM_RX_QUEUE);
- if (!ndev)
- return -ENOMEM;
-
+ if (!ndev) {
+ error = -ENOMEM;
+ goto pm_runtime_put;
+ }
info = of_device_get_match_data(&pdev->dev);

ndev->features = info->net_features;
ndev->hw_features = info->net_hw_features;

- error = reset_control_deassert(rstc);
- if (error) {
- free_netdev(ndev);
- return error;
- }
-
- pm_runtime_enable(&pdev->dev);
- pm_runtime_get_sync(&pdev->dev);
-
if (info->multi_irqs) {
if (info->err_mgmt_irqs)
irq = platform_get_irq_byname(pdev, "dia");
@@ -2878,8 +2879,9 @@ static int ravb_probe(struct platform_device *pdev)
clk_disable_unprepare(priv->refclk);
out_release:
free_netdev(ndev);
-
+pm_runtime_put:
pm_runtime_put(&pdev->dev);
+pm_runtime_disable:
pm_runtime_disable(&pdev->dev);
reset_control_assert(rstc);
return error;
--
2.39.2


2023-11-24 19:02:39

by Sergey Shtylyov

[permalink] [raw]
Subject: Re: [PATCH 02/13] net: ravb: Use pm_runtime_resume_and_get()

On 11/21/23 8:57 AM, claudiu beznea wrote:

[...]

>>> From: Claudiu Beznea <[email protected]>
>>>
>>> pm_runtime_get_sync() may return with error. In case it returns with error
>>> dev->power.usage_count needs to be decremented. pm_runtime_resume_and_get()
>>> takes care of this. Thus use it.
>>>
>>> Along with this pm_runtime_resume_and_get() and reset_control_deassert()
>>> were moved before alloc_etherdev_mqs() to simplify the error path.
>>
>> I don't see how it simplifies the error path...
>
> By not changing it... Actually, I took the other approach: you suggested in

But it does need to be changed! It's not currently in the reverse order
compared to the buildup path...

> patch 1 to re-arrange the error path, I did it the other way around:
> changed the initialization path...

That way you needlessly obfuscate (by moving the code around) the core
change you do in this patch: switching from calling pm_runtime_get_sync()
to calling pm_runtime_resume_and_get(). :-/

[...]

>>> Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
>>> Signed-off-by: Claudiu Beznea <[email protected]>
>> [...]

MBR, Sergey