This is a note to let you know that I've just added the patch titled
gpio: mpc8xxx: Don't overwrite default irq_set_type callback
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gpio-mpc8xxx-don-t-overwrite-default-irq_set_type-ca.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a8f999eebe81051a62bc2c70ed6290e91c7d5062
Author: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Date: Fri Nov 15 14:55:51 2019 +0200
gpio: mpc8xxx: Don't overwrite default irq_set_type callback
[ Upstream commit 4e50573f39229d5e9c985fa3b4923a8b29619ade ]
The per-SoC devtype structures can contain their own callbacks that
overwrite mpc8xxx_gpio_devtype_default.
The clear intention is that mpc8xxx_irq_set_type is used in case the SoC
does not specify a more specific callback. But what happens is that if
the SoC doesn't specify one, its .irq_set_type is de-facto NULL, and
this overwrites mpc8xxx_irq_set_type to a no-op. This means that the
following SoCs are affected:
- fsl,mpc8572-gpio
- fsl,ls1028a-gpio
- fsl,ls1088a-gpio
On these boards, the irq_set_type does exactly nothing, and the GPIO
controller keeps its GPICR register in the hardware-default state. On
the LS1028A, that is ACTIVE_BOTH, which means 2 interrupts are raised
even if the IRQ client requests LEVEL_HIGH. Another implication is that
the IRQs are not checked (e.g. level-triggered interrupts are not
rejected, although they are not supported).
Fixes: 82e39b0d8566 ("gpio: mpc8xxx: handle differences between incarnations at a single place")
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Link: https://lore.kernel.org/r/20191115125551.31061-1-olteanv@xxxxxxxxx
Tested-by: Michael Walle <michael@xxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c
index b863421ae730..a031cbcdf6ef 100644
--- a/drivers/gpio/gpio-mpc8xxx.c
+++ b/drivers/gpio/gpio-mpc8xxx.c
@@ -377,7 +377,8 @@ static int mpc8xxx_probe(struct platform_device *pdev)
* It's assumed that only a single type of gpio controller is available
* on the current machine, so overwriting global data is fine.
*/
- mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;
+ if (devtype->irq_set_type)
+ mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;
if (devtype->gpio_dir_out)
gc->direction_output = devtype->gpio_dir_out;
