[PATCH net-next 3/4] net: dsa: realtek: do not assert reset on remove

Luiz Angelo Daros de Luca posted 4 patches 1 year, 11 months ago
There is a newer version of this series
[PATCH net-next 3/4] net: dsa: realtek: do not assert reset on remove
Posted by Luiz Angelo Daros de Luca 1 year, 11 months ago
The necessity of asserting the reset on removal was previously questioned, as DSA's own cleanup methods should suffice to prevent traffic leakage[1].

When a driver has subdrivers controlled by devres, they will be unregistered after the main driver's .remove is executed. If it asserts a reset, the subdrivers will be unable to communicate with the hardware during their cleanup. For LEDs, this means that they will fail to turn off, resulting in a timeout error.

[1] https://lore.kernel.org/r/20240123215606.26716-9-luizluca@gmail.com/

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
 drivers/net/dsa/realtek/rtl83xx.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/net/dsa/realtek/rtl83xx.c b/drivers/net/dsa/realtek/rtl83xx.c
index d2e876805393..a9c1702431ef 100644
--- a/drivers/net/dsa/realtek/rtl83xx.c
+++ b/drivers/net/dsa/realtek/rtl83xx.c
@@ -290,16 +290,13 @@ EXPORT_SYMBOL_NS_GPL(rtl83xx_shutdown, REALTEK_DSA);
  * rtl83xx_remove() - Cleanup a realtek switch driver
  * @priv: realtek_priv pointer
  *
- * If a method is provided, this function asserts the hard reset of the switch
- * in order to avoid leaking traffic when the driver is gone.
+ * Placehold for common cleanup procedures.
  *
- * Context: Might sleep if priv->gdev->chip->can_sleep.
+ * Context: Any
  * Return: nothing
  */
 void rtl83xx_remove(struct realtek_priv *priv)
 {
-	/* leave the device reset asserted */
-	rtl83xx_reset_assert(priv);
 }
 EXPORT_SYMBOL_NS_GPL(rtl83xx_remove, REALTEK_DSA);
 

-- 
2.44.0
Re: [PATCH net-next 3/4] net: dsa: realtek: do not assert reset on remove
Posted by Linus Walleij 1 year, 11 months ago
On Sun, Mar 10, 2024 at 5:52 AM Luiz Angelo Daros de Luca
<luizluca@gmail.com> wrote:

> The necessity of asserting the reset on removal was previously questioned, as DSA's own cleanup methods should suffice to prevent traffic leakage[1].
>
> When a driver has subdrivers controlled by devres, they will be unregistered after the main driver's .remove is executed. If it asserts a reset, the subdrivers will be unable to communicate with the hardware during their cleanup. For LEDs, this means that they will fail to turn off, resulting in a timeout error.
>
> [1] https://lore.kernel.org/r/20240123215606.26716-9-luizluca@gmail.com/
>
> Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

The commit message needs some linebreaks :D

Other than that:
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij