Thread (5 messages) 5 messages, 4 authors, 2016-09-29

Re: [PATCH] pinctrl: rockchip: don't disable clk when irq mask is already set

From: Shawn Lin <shawn.lin@rock-chips.com>
Date: 2016-09-29 07:30:46
Also in: linux-rockchip, lkml

在 2016/9/27 6:35, Heiko Stuebner 写道:
Am Samstag, 24. September 2016, 18:24:11 CEST schrieb Shawn Lin:
quoted
On 2016/9/24 2:26, Jacob Chen wrote:
quoted
From: Jacob Chen <redacted>

In some drivers, disable_irq() call don't be symmetric with enable_irq()
, disable_irq() will be called before call free_irq().
Which upstream drivers you refer to?

Shouldn't it be the unbalanced call for these drivers?
quoted
But both disable_irq() and free_irq() will call
rockchip_irq_gc_mask_set_bit,>
 and clk_disable() will be called more times than clk_enable(), which will

cause bugs.

I think we can correct that by checking of mask.If mask is already set, do
nothing.
Looks like a little hacky to me.
that may be true, but on first glance I tend to agree with Jacob.
Look for example at (a driver using disable_irq I picked at random) drivertc/
rtcrs/-tps6586x.c .
yep, I took a quick look at the files you pointed to, and it seems
there should be the problems for what this patch to deal with. Probably
I didn't see this error since the drivers we was using happened to
handle it properly but maybe not for other drivers. I am okay if this
could solve problems for Jacob.
In its probe function it does devm_request_irq directly followed by
disable_irq on its alarm interrupt. The interrupt only gets enabled again if
the rtc alarm gets enabled. So you can easily run into the disable + free case
there as well. Similar probably in a lot of other drivers.


Heiko
quoted
quoted
Change-Id: If19912c7658253e15531c04db6c70fdbffd5960a
remove this.
quoted
Signed-off-by: Jacob Chen <redacted>
---

 drivers/pinctrl/pinctrl-rockchip.c | 4 ++++
 1 file changed, 4 insertions(+)
diff --git a/drivers/pinctrl/pinctrl-rockchip.c
b/drivers/pinctrl/pinctrl-rockchip.c index c6c04ac..9a8804a 100644
--- a/drivers/pinctrl/pinctrl-rockchip.c
+++ b/drivers/pinctrl/pinctrl-rockchip.c
@@ -2334,8 +2334,12 @@ static void rockchip_irq_gc_mask_clr_bit(struct
irq_data *d)>
 void rockchip_irq_gc_mask_set_bit(struct irq_data *d)
 {

 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);

+	struct irq_chip_type *ct = irq_data_get_chip_type(d);

 	struct rockchip_pin_bank *bank = gc->private;

+	if (*ct->mask_cache & d->mask)
+		return;
+

 	irq_gc_mask_set_bit(d);
 	clk_disable(bank->clk);

 }

--
2.7.4


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-- 
Best Regards
Shawn Lin
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