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pinctrl: st: avoid multiple mutex lock

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Using the sysfs inteface to inspect the pins configuration
the system can walk around a path which acquires the same
mutex twice.

On STiH407 platform, for example :
cat /sys/kernel/debug/pinctrl/920f080.pin-controller-front0/pinconf-pins
hangs the kernel and never returns.

With this patch the mutex is temporary freed.

Signed-off-by: Francesco Virlinzi <francesco.virlinzi@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Francesco VIRLINZI 2015-01-05 11:04:13 +01:00 committed by Linus Walleij
parent f2dd028c26
commit 96d16c3088
1 changed files with 3 additions and 1 deletions
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4
drivers/pinctrl/pinctrl-st.c
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@ -1012,8 +1012,10 @@ static void st_pinconf_dbg_show(struct pinctrl_dev *pctldev,
struct seq_file *s, unsigned pin_id)
{
unsigned long config;
st_pinconf_get(pctldev, pin_id, &config);
mutex_unlock(&pctldev->mutex);
st_pinconf_get(pctldev, pin_id, &config);
mutex_lock(&pctldev->mutex);
seq_printf(s, "[OE:%ld,PU:%ld,OD:%ld]\n"
"\t\t[retime:%ld,invclk:%ld,clknotdat:%ld,"
"de:%ld,rt-clk:%ld,rt-delay:%ld]",