Re: [PATCH 4/7] HID: sony: make the check for BUZZ_CONTROLLER more readable

On Mon, 1 Feb 2016 09:41:01 -0500
Frank Praznik [off-list ref] wrote:

quoted

On Jan 28, 2016, at 12:23, Antonio Ospite [off-list ref] wrote:

Use a positive test for BUZZ_CONTROLLER which is the particular case,
and leave the 'else' branch for the general case.

Signed-off-by: Antonio Ospite <redacted>
---
drivers/hid/hid-sony.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
index 8dcea69..3877101 100644
--- a/drivers/hid/hid-sony.c
+++ b/drivers/hid/hid-sony.c

@@ -1547,10 +1547,10 @@ static void buzz_set_leds(struct sony_sc *sc)

static void sony_set_leds(struct sony_sc *sc)
{
-	if (!(sc->quirks & BUZZ_CONTROLLER))
-		schedule_work(&sc->state_worker);
-	else
+	if (sc->quirks & BUZZ_CONTROLLER)
		buzz_set_leds(sc);
+	else
+		schedule_work(&sc->state_worker);
}

static void sony_led_set_brightness(struct led_classdev *led,
-- 
2.7.0

My nitpick here is that moving the common case to the ‘else’ branch
can mean more branch mispredictions.  This isn’t a particularly hot
piece of code, but I still prefer common-case first.

Hi Frank,

I see your point. Let's drop 4/7 for now then.
Jiri, will you apply the other patches? They have Frank's ACK.

Ultimately I’d really like to get rid of the special-case buzzer code
and just use a state worker like all of the other devices, but I don’t
have any buzzer controllers to test with and don’t know anyone who
does.

Agreed, a proper refactoring would be indeed better than my 4/7
proposal.

Looking at the history, support for the buzz controller was added by
Colin Leitner [off-list ref]

Ciao ciao,
   Antonio

-- 
Antonio Ospite
http://ao2.it

A: Because it messes up the order in which people normally read text.
   See http://en.wikipedia.org/wiki/Posting_style
Q: Why is top-posting such a bad thing?
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