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| author | Lukas Wunner <lukas@wunner.de> | 2018-01-10 18:32:10 +0300 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2018-01-10 21:00:14 +0300 |
| commit | e4b9e5b8618dc59f5de5cecf4e0188a3cdcd5648 (patch) | |
| tree | b643a9756385aeb1e09f5499c75853b612be7de9 /drivers/bluetooth/hci_bcm.c | |
| parent | 5954cdf1793a0e1296e495884669c79f9ef2b2b3 (diff) | |
| download | linux-e4b9e5b8618dc59f5de5cecf4e0188a3cdcd5648.tar.xz | |
Bluetooth: hci_bcm: Sleep instead of spinning
The driver calls mdelay(15) in the ->suspend, ->resume, ->runtime_suspend
and ->runtime_resume hook, however spinning for such a long period of
time is discouraged as per Documentation/timers/timers-howto.txt.
The use of mdelay() seems unnecessary, it is allowed to sleep in the
system sleep and runtime PM hooks (with the exception of ->suspend_noirq
and ->resume_noirq) and the driver itself also does not rely on a
non-sleeping ->runtime_resume as the only place where a synchronous
resume is performed, in bcm_dequeue(), is called from a work item in
hci_ldisc.c and hci_serdev.c.
So replace the mdelay(15) with msleep(15).
Note that the delay is inserted after asserting or deasserting the
device wake pin, but in bcm_gpio_set_power() that pin is asserted or
deasserted *without* observing a delay. It is thus unclear if the delay
is necessary at all. It is likewise unclear why it is exactly 15 ms,
the commit introducing it, 118612fb9165 ("Bluetooth: hci_bcm: Add
suspend/resume PM functions"), does not provide a rationale.
Cc: Frédéric Danis <frederic.danis.oss@gmail.com>
Suggested-and-reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'drivers/bluetooth/hci_bcm.c')
| -rw-r--r-- | drivers/bluetooth/hci_bcm.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c index 0929a264bffa..461364a00b20 100644 --- a/drivers/bluetooth/hci_bcm.c +++ b/drivers/bluetooth/hci_bcm.c @@ -656,7 +656,7 @@ static int bcm_suspend_device(struct device *dev) } bt_dev_dbg(bdev, "suspend, delaying 15 ms"); - mdelay(15); + msleep(15); return 0; } @@ -675,7 +675,7 @@ static int bcm_resume_device(struct device *dev) } bt_dev_dbg(bdev, "resume, delaying 15 ms"); - mdelay(15); + msleep(15); /* When this executes, the device has woken up already */ if (bdev->is_suspended && bdev->hu) { |