From: Hans Verkuil Date: Thu, 7 Feb 2019 11:49:48 +0000 (-0500) Subject: media: dvb-core: fix epoll() by calling poll_wait first X-Git-Tag: v5.1-rc1~88^2~77 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=c6f5c7c237fb7179f3652a46108086c9178eb419;p=linux.git media: dvb-core: fix epoll() by calling poll_wait first The epoll function expects that whenever the poll file op is called, the poll_wait function is also called. That didn't always happen in dvb_demux_poll(), dvb_dvr_poll() and dvb_ca_en50221_io_poll(). Fix this, otherwise epoll() can timeout when it shouldn't. Signed-off-by: Hans Verkuil Reviewed-by: Sean Young Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c index 1544e8cef564..f14a872d1268 100644 --- a/drivers/media/dvb-core/dmxdev.c +++ b/drivers/media/dvb-core/dmxdev.c @@ -1195,13 +1195,13 @@ static __poll_t dvb_demux_poll(struct file *file, poll_table *wait) struct dmxdev_filter *dmxdevfilter = file->private_data; __poll_t mask = 0; + poll_wait(file, &dmxdevfilter->buffer.queue, wait); + if ((!dmxdevfilter) || dmxdevfilter->dev->exit) return EPOLLERR; if (dvb_vb2_is_streaming(&dmxdevfilter->vb2_ctx)) return dvb_vb2_poll(&dmxdevfilter->vb2_ctx, file, wait); - poll_wait(file, &dmxdevfilter->buffer.queue, wait); - if (dmxdevfilter->state != DMXDEV_STATE_GO && dmxdevfilter->state != DMXDEV_STATE_DONE && dmxdevfilter->state != DMXDEV_STATE_TIMEDOUT) @@ -1346,13 +1346,13 @@ static __poll_t dvb_dvr_poll(struct file *file, poll_table *wait) dprintk("%s\n", __func__); + poll_wait(file, &dmxdev->dvr_buffer.queue, wait); + if (dmxdev->exit) return EPOLLERR; if (dvb_vb2_is_streaming(&dmxdev->dvr_vb2_ctx)) return dvb_vb2_poll(&dmxdev->dvr_vb2_ctx, file, wait); - poll_wait(file, &dmxdev->dvr_buffer.queue, wait); - if (((file->f_flags & O_ACCMODE) == O_RDONLY) || dmxdev->may_do_mmap) { if (dmxdev->dvr_buffer.error) diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb-core/dvb_ca_en50221.c index 4d371cea0d5d..ebf1e3b03819 100644 --- a/drivers/media/dvb-core/dvb_ca_en50221.c +++ b/drivers/media/dvb-core/dvb_ca_en50221.c @@ -1797,6 +1797,8 @@ static __poll_t dvb_ca_en50221_io_poll(struct file *file, poll_table *wait) dprintk("%s\n", __func__); + poll_wait(file, &ca->wait_queue, wait); + if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1) mask |= EPOLLIN; @@ -1804,9 +1806,6 @@ static __poll_t dvb_ca_en50221_io_poll(struct file *file, poll_table *wait) if (mask) return mask; - /* wait for something to happen */ - poll_wait(file, &ca->wait_queue, wait); - if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1) mask |= EPOLLIN;