From: Takashi Iwai <tiwai@suse.de> To: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: alsa-devel@alsa-project.org, tglx@linutronix.de, Jaroslav Kysela <perex@perex.cz>, linux-usb@vger.kernel.org Subject: [8/9] ALSA: usx2y: usbusx2yaudio: use usb_fill_int_urb() Date: Wed, 20 Jun 2018 16:52:45 +0200 [thread overview] Message-ID: <s5hzhzpldc2.wl-tiwai@suse.de> (raw) On Wed, 20 Jun 2018 16:39:22 +0200, Sebastian Andrzej Siewior wrote: > > 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. Yes, but it's no hot path, and the code won't bigger. And I bet you won't notice any performance lost by that :) > What about pulling the > overflow-mul macro out of malloc_array() and doing this instead: Well, it's neither smaller nor more readable... thanks, Takashi > > ----------- >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 <perex@perex.cz> > Cc: Takashi Iwai <tiwai@suse.com> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@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 > --- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
WARNING: multiple messages have this Message-ID (diff)
From: Takashi Iwai <tiwai@suse.de> To: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: alsa-devel@alsa-project.org, linux-usb@vger.kernel.org, tglx@linutronix.de Subject: Re: [PATCH 8/9] ALSA: usx2y: usbusx2yaudio: use usb_fill_int_urb() Date: Wed, 20 Jun 2018 16:52:45 +0200 [thread overview] Message-ID: <s5hzhzpldc2.wl-tiwai@suse.de> (raw) In-Reply-To: <20180620143922.nkcazvbcrmkyvm2c@linutronix.de> On Wed, 20 Jun 2018 16:39:22 +0200, Sebastian Andrzej Siewior wrote: > > 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. Yes, but it's no hot path, and the code won't bigger. And I bet you won't notice any performance lost by that :) > What about pulling the > overflow-mul macro out of malloc_array() and doing this instead: Well, it's neither smaller nor more readable... thanks, Takashi > > ----------- >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 <perex@perex.cz> > Cc: Takashi Iwai <tiwai@suse.com> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@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 >
next reply other threads:[~2018-06-20 14:52 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-06-20 14:52 Takashi Iwai [this message] 2018-06-20 14:52 ` [PATCH 8/9] ALSA: usx2y: usbusx2yaudio: use usb_fill_int_urb() Takashi Iwai -- strict thread matches above, loose matches on Subject: below -- 2018-06-22 10:14 [6/9] ALSA: usb: caiaq: " Sebastian Andrzej Siewior 2018-06-22 10:14 ` [PATCH 6/9] " Sebastian Andrzej Siewior 2018-06-22 10:01 [6/9] " Daniel Mack 2018-06-22 10:01 ` [PATCH 6/9] " Daniel Mack 2018-06-22 8:49 [6/9] " Takashi Iwai 2018-06-22 8:49 ` [PATCH 6/9] " Takashi Iwai 2018-06-21 21:16 [6/9] " Sebastian Andrzej Siewior 2018-06-21 21:16 ` [PATCH 6/9] " Sebastian Andrzej Siewior 2018-06-21 20:19 [6/9] " Daniel Mack 2018-06-21 20:19 ` [PATCH 6/9] " Daniel Mack 2018-06-21 20:18 [5/9] ALSA: usb: caiaq: audio: use irqsave() in USB's complete callback Daniel Mack 2018-06-21 20:18 ` [PATCH 5/9] " Daniel Mack 2018-06-20 16:20 [8/9] ALSA: usx2y: usbusx2yaudio: use usb_fill_int_urb() Takashi Iwai 2018-06-20 16:20 ` [PATCH 8/9] " Takashi Iwai 2018-06-20 15:47 [8/9] " Sebastian Andrzej Siewior 2018-06-20 15:47 ` [PATCH 8/9] " Sebastian Andrzej Siewior 2018-06-20 15:38 [8/9] " Sebastian Andrzej Siewior 2018-06-20 15:38 ` [PATCH 8/9] " Sebastian Andrzej Siewior 2018-06-20 14:39 [8/9] " Sebastian Andrzej Siewior 2018-06-20 14:39 ` [PATCH 8/9] " Sebastian Andrzej Siewior 2018-06-20 14:00 [4/9,v2] ALSA: usb-audio: " Takashi Iwai 2018-06-20 14:00 ` [PATCH 4/9 v2] " Takashi Iwai 2018-06-20 13:56 [4/9,v2] " Takashi Iwai 2018-06-20 13:56 ` [PATCH 4/9 v2] " Takashi Iwai 2018-06-20 13:52 [4/9,v2] " Sebastian Andrzej Siewior 2018-06-20 13:52 ` [PATCH 4/9 v2] " Sebastian Andrzej Siewior 2018-06-20 13:21 [4/9,v2] " Takashi Iwai 2018-06-20 13:21 ` [PATCH 4/9 v2] " Takashi Iwai 2018-06-20 12:51 [8/9] ALSA: usx2y: usbusx2yaudio: " Takashi Iwai 2018-06-20 12:51 ` [PATCH 8/9] " Takashi Iwai 2018-06-20 9:38 [4/9,v2] ALSA: usb-audio: " Sebastian Andrzej Siewior 2018-06-20 9:38 ` [PATCH 4/9 v2] " Sebastian Andrzej Siewior 2018-06-20 8:23 [4/9] " Sergei Shtylyov 2018-06-20 8:23 ` [PATCH 4/9] " Sergei Shtylyov 2018-06-19 21:55 [9/9] ALSA: usx2y: usx2yhwdeppcm: " Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 9/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 [8/9] ALSA: usx2y: usbusx2yaudio: " Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 8/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 [7/9] ALSA: usb-midi: use irqsave() in USB's complete callback Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 7/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 [6/9] ALSA: usb: caiaq: use usb_fill_int_urb() Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 6/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 [5/9] ALSA: usb: caiaq: audio: use irqsave() in USB's complete callback Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 5/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 [4/9] ALSA: usb-audio: use usb_fill_int_urb() Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 4/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 [3/9] ALSA: ua101: " Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 3/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 [2/9] ALSA: line6: " Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 2/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 [1/9] ALSA: 6fire: " Sebastian Andrzej Siewior 2018-06-19 21:55 ` [PATCH 1/9] " Sebastian Andrzej Siewior 2018-06-19 21:55 ALSA: use irqsave() in URB completion + usb_fill_int_urb Sebastian Andrzej Siewior 2018-06-20 12:55 ` Takashi Iwai
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