ALSA: ice1724: Fix sleep-in-atomic in Infrasonic Quartet support code

Jia-Ju Bai reported a possible sleep-in-atomic scenario in the ice1724
driver with Infrasonic Quartet support code: namely, ice->set_rate
callback gets called inside ice->reg_lock spinlock, while the callback
in quartet.c holds ice->gpio_mutex.

This patch fixes the invalid call: it simply moves the calls of
ice->set_rate and ice->set_mclk callbacks outside the spinlock.

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/5d43135e-73b9-a46a-2155-9e91d0dcdf83@gmail.com
Link: https://lore.kernel.org/r/20191218192606.12866-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/ice1712/ice1724.c b/sound/pci/ice1712/ice1724.c
index c80a16ee6e76171ed5123e0c374b83afbd1e6545..242542e23d283b31e01a1154fdf4103d9c9a3132 100644 (file)
--- a/sound/pci/ice1712/ice1724.c
+++ b/sound/pci/ice1712/ice1724.c
@@ -647,6 +647,7 @@ static int snd_vt1724_set_pro_rate(struct snd_ice1712 *ice, unsigned int rate,
        unsigned long flags;
        unsigned char mclk_change;
        unsigned int i, old_rate;
+       bool call_set_rate = false;
 
        if (rate > ice->hw_rates->list[ice->hw_rates->count - 1])
                return -EINVAL;
@@ -670,7 +671,7 @@ static int snd_vt1724_set_pro_rate(struct snd_ice1712 *ice, unsigned int rate,
                 * setting clock rate for internal clock mode */
                old_rate = ice->get_rate(ice);
                if (force || (old_rate != rate))
-                       ice->set_rate(ice, rate);
+                       call_set_rate = true;
                else if (rate == ice->cur_rate) {
                        spin_unlock_irqrestore(&ice->reg_lock, flags);
                        return 0;
@@ -678,12 +679,14 @@ static int snd_vt1724_set_pro_rate(struct snd_ice1712 *ice, unsigned int rate,
        }
 
        ice->cur_rate = rate;
+       spin_unlock_irqrestore(&ice->reg_lock, flags);
+
+       if (call_set_rate)
+               ice->set_rate(ice, rate);
 
        /* setting master clock */
        mclk_change = ice->set_mclk(ice, rate);
 
-       spin_unlock_irqrestore(&ice->reg_lock, flags);
-
        if (mclk_change && ice->gpio.i2s_mclk_changed)
                ice->gpio.i2s_mclk_changed(ice);
        if (ice->gpio.set_pro_rate)