On 2018-06-20 14:51:12 [+0200], Takashi Iwai wrote:
> On Tue, 19 Jun 2018 23:55:20 +0200,
> Sebastian Andrzej Siewior wrote:
> > - (*purb)->transfer_buffer =
> > - kmalloc_array(subs->maxpacksize,
> > - nr_of_packs(), GFP_KERNEL);
> > - if (NULL == (*purb)->transfer_buffer) {
> > + len = subs->maxpacksize * nr_of_packs();
> > + buf = kmalloc(len, GFP_KERNEL);
>
> I'd keep kmalloc_array() as is, and just put subs->maxpacksize *
> nr_of_packs() in usb_fill_int_urb(). Otherwise it's a step backward.
but then we end up with two multiplications. What about pulling the
overflow-mul macro out of malloc_array() and doing this instead:
----------- >8
Subject: [PATCH 8/9 v2] ALSA: usx2y: usbusx2yaudio: use usb_fill_int_urb()
Using usb_fill_int_urb() helps to find code which initializes an
URB. A grep for members of the struct (like ->complete) reveal lots
of other things, too.
The "&& !(*purb)->transfer_buffer" check has been removed because the
URB has been freshly allocated a few lines above so ->transfer_buffer
has to be NULL here.
The `dev' and `transfer_size' assignments have been moved from
usX2Y_urbs_start() to usX2Y_urbs_allocate() because they don't change
overtime.
The multiplication via check_mul_overflow() has been extracted from
kmalloc_array() to avoid two multiplication (one with overflow check and
one without for the length argument). This requires to change the type
`maxpacksize' to int so there is only one type involved in the
multiplication.
Cc: Jaroslav Kysela <pe...@perex.cz>
Cc: Takashi Iwai <ti...@suse.com>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
sound/usb/usx2y/usbusx2y.h | 2 +-
sound/usb/usx2y/usbusx2yaudio.c | 38 ++++++++++++++++-----------------
2 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/sound/usb/usx2y/usbusx2y.h b/sound/usb/usx2y/usbusx2y.h
index e0f77172ce8f..2bec412589b4 100644
--- a/sound/usb/usx2y/usbusx2y.h
+++ b/sound/usb/usx2y/usbusx2y.h
@@ -56,7 +56,7 @@ struct snd_usX2Y_substream {
struct snd_pcm_substream *pcm_substream;
int endpoint;
- unsigned int maxpacksize; /* max packet size in
bytes */
+ int maxpacksize; /* max packet size in
bytes */
atomic_t state;
#define state_STOPPED 0
diff --git a/sound/usb/usx2y/usbusx2yaudio.c b/sound/usb/usx2y/usbusx2yaudio.c
index 2b833054e3b0..e5580cb59858 100644
--- a/sound/usb/usx2y/usbusx2yaudio.c
+++ b/sound/usb/usx2y/usbusx2yaudio.c
@@ -425,33 +425,35 @@ static int usX2Y_urbs_allocate(struct snd_usX2Y_substream
*subs)
/* allocate and initialize data urbs */
for (i = 0; i < NRURBS; i++) {
struct urb **purb = subs->urb + i;
+ void *buf = NULL;
+ int len = 0;
+
if (*purb) {
usb_kill_urb(*purb);
continue;
}
*purb = usb_alloc_urb(nr_of_packs(), GFP_KERNEL);
- if (NULL == *purb) {
- usX2Y_urbs_release(subs);
- return -ENOMEM;
- }
- if (!is_playback && !(*purb)->transfer_buffer) {
+ if (NULL == *purb)
+ goto err_free;
+
+ if (!is_playback) {
/* allocate a capture buffer per urb */
- (*purb)->transfer_buffer =
- kmalloc_array(subs->maxpacksize,
- nr_of_packs(), GFP_KERNEL);
- if (NULL == (*purb)->transfer_buffer) {
- usX2Y_urbs_release(subs);
- return -ENOMEM;
- }
+ if (check_mul_overflow(subs->maxpacksize,
+ nr_of_packs(),
+ &len))
+ goto err_free;
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ goto err_free;
}
- (*purb)->dev = dev;
- (*purb)->pipe = pipe;
+ usb_fill_int_urb(*purb, dev, pipe, buf, len,
+ i_usX2Y_subs_startup, subs, 1);
(*purb)->number_of_packets = nr_of_packs();
- (*purb)->context = subs;
- (*purb)->interval = 1;
- (*purb)->complete = i_usX2Y_subs_startup;
}
return 0;
+err_free:
+ usX2Y_urbs_release(subs);
+ return -ENOMEM;
}
static void usX2Y_subs_startup(struct snd_usX2Y_substream *subs)
@@ -485,12 +487,10 @@ static int usX2Y_urbs_start(struct snd_usX2Y_substream
*subs)
unsigned long pack;
if (0 == i)
atomic_set(&subs->state, state_STARTING3);
- urb->dev = usX2Y->dev;
for (pack = 0; pack < nr_of_packs(); pack++) {
urb->iso_frame_desc[pack].offset =
subs->maxpacksize * pack;
urb->iso_frame_desc[pack].length =
subs->maxpacksize;
}
- urb->transfer_buffer_length = subs->maxpacksize *
nr_of_packs();
if ((err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
snd_printk (KERN_ERR "cannot submit datapipe
for urb %d, err = %d\n", i, err);
err = -EPIPE;
--
2.17.1
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