On Wed, Jan 07, 2015 at 10:41:24AM +0100, Olliver Schinagl wrote: > HEy Dmitry, > > On 07-01-15 09:26, Dmitry Torokhov wrote: > >On Wed, Jan 07, 2015 at 09:19:28AM +0100, Olliver Schinagl wrote: > >>Hey Dmitry, > >> > >>On 07-01-15 08:57, Dmitry Torokhov wrote: > >>>Hi Olliver, > >>> > >>>On Wed, Jan 07, 2015 at 08:31:06AM +0100, Olliver Schinagl wrote: > >>>>From: Olliver Schinagl <oliver@xxxxxxxxxxx> > >>>> > >>>>Almost all of the speaker drivers under input manipulate the ev bits > >>>>directly, which is not needed, as there is a helper available. > >>>> > >>>>This patch makes use of the helper for the speaker drivers. > >>>> > >>>>Signed-off-by: Olliver Schinagl <oliver@xxxxxxxxxxx> > >>>>--- > >>>> drivers/input/misc/cm109.c | 4 ++-- > >>>> drivers/input/misc/ixp4xx-beeper.c | 5 ++--- > >>>> drivers/input/misc/m68kspkr.c | 5 ++--- > >>>> drivers/input/misc/pcspkr.c | 5 ++--- > >>>> drivers/input/misc/pwm-beeper.c | 5 +---- > >>>> drivers/input/misc/sparcspkr.c | 6 ++---- > >>>> 6 files changed, 11 insertions(+), 19 deletions(-) > >>>> > >>>>diff --git a/drivers/input/misc/cm109.c b/drivers/input/misc/cm109.c > >>>>index 9365535..8e41070 100644 > >>>>--- a/drivers/input/misc/cm109.c > >>>>+++ b/drivers/input/misc/cm109.c > >>>>@@ -767,10 +767,10 @@ static int cm109_usb_probe(struct usb_interface *intf, > >>>> input_dev->keycodesize = sizeof(unsigned char); > >>>> input_dev->keycodemax = ARRAY_SIZE(dev->keymap); > >>>>- input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_SND); > >>>>- input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE); > >>>>+ input_set_capability(input_dev, EV_SND, SND_BELL | SND_TONE); > >>>No, input_set_capability() takes single event code, not bitmask. The > >>>fact that it works for these 2 values of SND events is pure coincidence > >>>(the old code wasn't much better though). > >Ah, not, it does not work at all. Instead of setting bits 1 and 2 your > >code sets bit 3 in dev->sndbit. > > > >>What do you suggest we should do then? Fix input_set_capability to > >>take bit masks? or multiline events? > >>I'm not sure why __set_bits() wouldn't work for bitmasks, could you > >>educate me? > >Call it once per event: > > > > input_set_capability(input_dev, EV_SND, SND_BELL); > > input_set_capability(input_dev, EV_SND, SND_TONE); > roger, done > > > >>>> /* register available key events */ > >>>>+ input_dev->evbit[0] = BIT_MASK(EV_KEY); > >>>Would prefer __set_bit(EV_KEY, input_dev->evbit); here instead. > >>I only moved the EV_KEY bit from above to its appropiate place here. > >The original code was setting combination of bits; here we set single > >one and __set_bit() is cleaner IMO. > The documentation contradicts this actually, it says to use > set_bit() first, but favors the direct writing as above as it is > 'shorter in some cases'. Right, sometimes, when you need to set 3-4 values on evbit (that is pretty much guaranteed to fit into one long word) it is shoerted to write input->evbit[0] = BIT(EV_A) | BIT(EV_B) | BIT(EV_C); it is shorted, but it is not that great as it relies on knowledge of EV_* values. Now relying on that knowledge is pretty safe as they form userspace ABI and will not be changed, only extended. But nowadays I prefer using __set_bit() or input_set_capability() if possible. > > Furthermore, I'm a little confused as what the purpose of > input_set_capability() is, if we use set_bits (or __set_bits) here. > It appears we use set_bits here because it is manipulating several > entries in the array (well atleast index 0) and > set_input_capability() doesn't handle arrays? But when I look at > struct input_dev, all those entries are arrays, including sndbit. So > we only use set_input_capabilities when manipulating index 0 when > its the only one? Feels a little strange to me, but probably is my > lack of knowledge herin, so appologies for that. __set_bit() sets arbitrary bit in memory started at given address. So to set bit 65 (or bit 1 in the 3rd element of u32 array a) on you do: __set_bit(65, a); input_set_capability() is a wrapper that does set both evbit and appropriate *bit for given event type and event code and caller does not need to know all the details about bitmap names inside input device structure. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
