[RFC PATCH] pinctrl: rockchip: add irq_shutdown

On Fri, Jun 30, 2017 at 09:24:54AM +0800, Jeffy Chen wrote:

On 06/30/2017 06:05 AM, Brian Norris wrote:

quoted

On Fri, Jun 23, 2017 at 09:03:39PM +0800, Jeffy Chen wrote:

quoted

Currently the rockchip pinctrl driver would try to enable/disable the
gpio bank clk when enable/disable an irq.

So when the irq core trying to shutdown an already disabled irq, it
would result in unbalanced clk disable request:
[   35.911955] WARNING: at drivers/clk/clk.c:680
...
[   37.272271] Call trace:
[   37.274729] [<ffffffc0007ac270>] clk_core_disable+0x28/0x194
[   37.280395] [<ffffffc0007ac6a8>] clk_disable+0x34/0x48
[   37.285544] [<ffffffc0004f3bf0>] rockchip_irq_disable+0x30/0x3c
[   37.291472] [<ffffffc00027a7e0>] __irq_disable+0x40/0x64
[   37.296791] [<ffffffc00027a86c>] irq_shutdown+0x68/0x8c
[   37.302023] [<ffffffc0002777fc>] __free_irq+0x110/0x218
[   37.307254] [<ffffffc0002779a8>] free_irq+0x54/0x64
[   37.312138] [<ffffffc00027ba24>] devm_irq_release+0x24/0x30

Add an irq_shutdown callback, and do a sanity check for irq state to
prevent that.

IMO, this patch is completely the wrong approach. Either we:

(a) follow the current semantics of the irqchip core handling (which
tglx described more or less as "no refcounting; no guarantee that
enable/disable are balanced") or

(b) fix the irqchip core to provide the above guarantee

right, since we have:
bf22ff45 genirq: Avoid unnecessary low level irq function calls
d829b8f genirq: Set irq masked state when initializing irq_desc

this issue should be fixed now.

Oh, I didn't notice Thomas applied those. I'll have to take a look.

Brian