| Message ID | 20201113101241.GB168908@mwanda (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ALSA: firewire: Clean up a locking issue in copy_resp_to_buf() | expand |
Hi, On Fri, Nov 13, 2020 at 01:12:41PM +0300, Dan Carpenter wrote: > The spin_lock/unlock_irq() functions cannot be nested. The problem is > that presumably we would want the IRQs to be re-enabled on the second > call the spin_unlock_irq() but instead it will be enabled at the first > call so IRQs will be enabled earlier than expected. > > In this situation the copy_resp_to_buf() function is only called from > one function and it is called with IRQs disabled. We can just use > the regular spin_lock/unlock() functions. > > Fixes: 555e8a8f7f14 ("ALSA: fireworks: Add command/response functionality into hwdep interface") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > sound/firewire/fireworks/fireworks_transaction.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Indeed. It's bad to use the two pairs by nesting. Thanks for the patch and your care. Acked-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> > diff --git a/sound/firewire/fireworks/fireworks_transaction.c b/sound/firewire/fireworks/fireworks_transaction.c > index 0f533f5bd960..9f8c53b39f95 100644 > --- a/sound/firewire/fireworks/fireworks_transaction.c > +++ b/sound/firewire/fireworks/fireworks_transaction.c > @@ -123,7 +123,7 @@ copy_resp_to_buf(struct snd_efw *efw, void *data, size_t length, int *rcode) > t = (struct snd_efw_transaction *)data; > length = min_t(size_t, be32_to_cpu(t->length) * sizeof(u32), length); > > - spin_lock_irq(&efw->lock); > + spin_lock(&efw->lock); > > if (efw->push_ptr < efw->pull_ptr) > capacity = (unsigned int)(efw->pull_ptr - efw->push_ptr); > @@ -190,7 +190,7 @@ handle_resp_for_user(struct fw_card *card, int generation, int source, > > copy_resp_to_buf(efw, data, length, rcode); > end: > - spin_unlock_irq(&instances_lock); > + spin_unlock(&instances_lock); > } > > static void > -- > 2.28.0 Regards Takashi Sakamoto
On Fri, 13 Nov 2020 11:12:41 +0100, Dan Carpenter wrote: > > The spin_lock/unlock_irq() functions cannot be nested. The problem is > that presumably we would want the IRQs to be re-enabled on the second > call the spin_unlock_irq() but instead it will be enabled at the first > call so IRQs will be enabled earlier than expected. > > In this situation the copy_resp_to_buf() function is only called from > one function and it is called with IRQs disabled. We can just use > the regular spin_lock/unlock() functions. > > Fixes: 555e8a8f7f14 ("ALSA: fireworks: Add command/response functionality into hwdep interface") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- Thanks, applied now with Cc to stable. Takashi
diff --git a/sound/firewire/fireworks/fireworks_transaction.c b/sound/firewire/fireworks/fireworks_transaction.c index 0f533f5bd960..9f8c53b39f95 100644 --- a/sound/firewire/fireworks/fireworks_transaction.c +++ b/sound/firewire/fireworks/fireworks_transaction.c @@ -123,7 +123,7 @@ copy_resp_to_buf(struct snd_efw *efw, void *data, size_t length, int *rcode) t = (struct snd_efw_transaction *)data; length = min_t(size_t, be32_to_cpu(t->length) * sizeof(u32), length); - spin_lock_irq(&efw->lock); + spin_lock(&efw->lock); if (efw->push_ptr < efw->pull_ptr) capacity = (unsigned int)(efw->pull_ptr - efw->push_ptr); @@ -190,7 +190,7 @@ handle_resp_for_user(struct fw_card *card, int generation, int source, copy_resp_to_buf(efw, data, length, rcode); end: - spin_unlock_irq(&instances_lock); + spin_unlock(&instances_lock); } static void
The spin_lock/unlock_irq() functions cannot be nested. The problem is that presumably we would want the IRQs to be re-enabled on the second call the spin_unlock_irq() but instead it will be enabled at the first call so IRQs will be enabled earlier than expected. In this situation the copy_resp_to_buf() function is only called from one function and it is called with IRQs disabled. We can just use the regular spin_lock/unlock() functions. Fixes: 555e8a8f7f14 ("ALSA: fireworks: Add command/response functionality into hwdep interface") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- sound/firewire/fireworks/fireworks_transaction.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)