From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Colin Pitrat <colin.pitrat@gmail.com>
Cc: linus.walleij@linaro.org, gnurou@gmail.com,
rebecca.swee.fun.chang@intel.com, linux-gpio@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] gpio: sch: Fix Oops on module load on Asus Eee PC 1201
Date: Mon, 9 May 2016 10:02:45 +0300 [thread overview]
Message-ID: <20160509070245.GJ15974@lahna.fi.intel.com> (raw)
In-Reply-To: <20160506214917.GA1691@pitrat4.localdomain>
On Fri, May 06, 2016 at 10:49:25PM +0100, Colin Pitrat wrote:
> This fixes the issue descirbe in bug 117531.
Can you include the oops log in the changelog as well?
> It's a regression introduced in linux 4.5 that causes a Oops at load of
> gpio_sch and prevents powering off the computer.
>
> The patch consist in reverting commit 737c8fccf1c5b2aae3c6d9a66dce17e35fc39b71
> (a.k.a 'gpio: sch: use gpiochip data pointer') that causes this regression.
> However, although it does work for me, I'm not sure of the impact of reverting
> only this part of the patch.
What happens here is that after the change we expect that
gpiochip_get_data() returns the correct pointer but that only happens
after devm_gpiochip_add_data() is called, which is the last call in
sch_gpio_probe(). Before that we call sch_gpio_reg_set() couple of times
if the device id is PCI_DEVICE_ID_INTEL_SCH_LPC and that causes NULL
pointer dereference.
I think better fix is to make sch_gpio_reg_get() and sch_gpio_reg_set()
take pointer to struct sch_gpio and use that directly like:
static void sch_gpio_reg_set(struct sch_gpio *sch, unsigned gpio,
unsigned reg, int val)
{
...
}
Neither function actually need gc for anything anyway.
next prev parent reply other threads:[~2016-05-09 7:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-06 21:49 [PATCH] gpio: sch: Fix Oops on module load on Asus Eee PC 1201 Colin Pitrat
2016-05-07 19:37 ` Colin Pitrat
2016-05-09 7:02 ` Mika Westerberg [this message]
2016-05-09 19:37 ` Colin Pitrat
[not found] ` <CABy3NjSJTygdP3POxQQqxDA6=Jx4DeQ47KONASfm46kei7wBDQ@mail.gmail.com>
2016-06-17 8:10 ` Mika Westerberg
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