2018-03-28 06:18:11

by Nicolas Boichat

Subject: [PATCH] HID: google: Enable PM Full On mode when adjusting backlight

From: Haridhar Kalvala <[email protected]>

hammer LED backlight brightness is not getting set when USB
device is in suspend state.

This patch fixes the issue by requesting USB HID device to be
in FULLON mode, so that sending hardware output report and
hardware raw request won't fail to set brightness, and set
device back to NORMAL mode once this call returns.

Signed-off-by: Haridhar Kalvala <[email protected]>
Reviewed-by: Dmitry Torokhov <[email protected]>
Signed-off-by: Nicolas Boichat <[email protected]>
---
drivers/hid/hid-google-hammer.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

Changes from version on Chromium OS gerrit
(https://chromium-review.googlesource.com/735259):
- Reworded and reflowed commit message, as well as comment in code.

diff --git a/drivers/hid/hid-google-hammer.c b/drivers/hid/hid-google-hammer.c
index 6486469ce0f64..7b8e17b03cb86 100644
--- a/drivers/hid/hid-google-hammer.c
+++ b/drivers/hid/hid-google-hammer.c
@@ -41,6 +41,16 @@ static int hammer_kbd_brightness_set_blocking(struct led_classdev *cdev,
led->buf[0] = 0;
led->buf[1] = br;

+ /*
+ * Request USB HID device to be in Full On mode, so that sending
+ * hardware output report and hardware raw request won't fail.
+ */
+ ret = hid_hw_power(led->hdev, PM_HINT_FULLON);
+ if (ret < 0) {
+ hid_err(led->hdev, "failed: device not resumed %d\n", ret);
+ return ret;
+ }
+
ret = hid_hw_output_report(led->hdev, led->buf, sizeof(led->buf));
if (ret == -ENOSYS)
ret = hid_hw_raw_request(led->hdev, 0, led->buf,
@@ -50,6 +60,10 @@ static int hammer_kbd_brightness_set_blocking(struct led_classdev *cdev,
if (ret < 0)
hid_err(led->hdev, "failed to set keyboard backlight: %d\n",
ret);
+
+ /* Request USB HID device back to Normal Mode. */
+ hid_hw_power(led->hdev, PM_HINT_NORMAL);
+
return ret;
}

--
2.17.0.rc1.321.gba9d0f2565-goog

2018-03-28 14:15:04

by Jiri Kosina

Subject: Re: [PATCH] HID: google: Enable PM Full On mode when adjusting backlight

On Wed, 28 Mar 2018, Nicolas Boichat wrote:

> From: Haridhar Kalvala <[email protected]>
>
> hammer LED backlight brightness is not getting set when USB
> device is in suspend state.
>
> This patch fixes the issue by requesting USB HID device to be
> in FULLON mode, so that sending hardware output report and
> hardware raw request won't fail to set brightness, and set
> device back to NORMAL mode once this call returns.
>
> Signed-off-by: Haridhar Kalvala <[email protected]>
> Reviewed-by: Dmitry Torokhov <[email protected]>
> Signed-off-by: Nicolas Boichat <[email protected]>

Applied to for-4.17/google-hammer. Thanks,

--
Jiri Kosina
SUSE Labs