diff options
| author | Davidlohr Bueso <dave@stgolabs.net> | 2021-01-11 07:28:55 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-12 14:52:28 +0300 |
| commit | 8653d71ce3763aedcf3d2331f59beda3fecd79e4 (patch) | |
| tree | c7b041caeb00e3466c430d4280247148cc8b3812 /drivers/usb/gadget | |
| parent | 0c0a20f6da04780b94e3ccc43101dde6f536ab37 (diff) | |
| download | linux-8653d71ce3763aedcf3d2331f59beda3fecd79e4.tar.xz | |
usb/gadget: f_midi: Replace tasklet with work
Currently a tasklet is used to transmit input substream buffer
data. However, tasklets have long been deprecated as being too
heavy on the system by running in irq context - and this is not
a performance critical path. If a higher priority process wants
to run, it must wait for the tasklet to finish before doing so.
Deferring work to a workqueue and executing in process context
should be fine considering the callback already does
f_midi_do_transmit() under the transmit_lock and thus changes in
semantics are ok regarding concurrency - tasklets being serialized
against itself.
Cc: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210111042855.73289-1-dave@stgolabs.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/function/f_midi.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index 8fff995b8dd5..71a1a26e85c7 100644 --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -87,7 +87,7 @@ struct f_midi { struct snd_rawmidi_substream *out_substream[MAX_PORTS]; unsigned long out_triggered; - struct tasklet_struct tasklet; + struct work_struct work; unsigned int in_ports; unsigned int out_ports; int index; @@ -698,9 +698,11 @@ drop_out: f_midi_drop_out_substreams(midi); } -static void f_midi_in_tasklet(struct tasklet_struct *t) +static void f_midi_in_work(struct work_struct *work) { - struct f_midi *midi = from_tasklet(midi, t, tasklet); + struct f_midi *midi; + + midi = container_of(work, struct f_midi, work); f_midi_transmit(midi); } @@ -737,7 +739,7 @@ static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up) VDBG(midi, "%s() %d\n", __func__, up); midi->in_ports_array[substream->number].active = up; if (up) - tasklet_hi_schedule(&midi->tasklet); + queue_work(system_highpri_wq, &midi->work); } static int f_midi_out_open(struct snd_rawmidi_substream *substream) @@ -875,7 +877,7 @@ static int f_midi_bind(struct usb_configuration *c, struct usb_function *f) int status, n, jack = 1, i = 0, endpoint_descriptor_index = 0; midi->gadget = cdev->gadget; - tasklet_setup(&midi->tasklet, f_midi_in_tasklet); + INIT_WORK(&midi->work, f_midi_in_work); status = f_midi_register_card(midi); if (status < 0) goto fail_register; |