[PATCH 6.18 126/752] media: dvb-core: dmxdevfilter must always flush bufs

Sasha Levin
2026-02-28T17:49:55Z

From: Hans Verkuil <hverkuil@xs4all.nl>

[ Upstream commit c4e620eccbef76aa5564ebb295e23d6540e27215 ]

Currently the buffers are being filled until full, which works fine
for the transport stream, but not when reading sections, those have
to be returned to userspace immediately, otherwise dvbv5-scan will
just wait forever.

Add a 'flush' argument to dvb_vb2_fill_buffer to indicate whether
the buffer must be flushed or wait until it is full.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/dvb-core/dmxdev.c | 8 ++++----
drivers/media/dvb-core/dvb_vb2.c | 5 +++--
include/media/dvb_vb2.h | 6 ++++--
3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
index 151177e5a06d8..8a9cca6da3e0e 100644
--- a/drivers/media/dvb-core/dmxdev.c
+++ b/drivers/media/dvb-core/dmxdev.c
@@ -397,11 +397,11 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len,
if (dvb_vb2_is_streaming(&dmxdevfilter->vb2_ctx)) {
ret = dvb_vb2_fill_buffer(&dmxdevfilter->vb2_ctx,
buffer1, buffer1_len,
- buffer_flags);
+ buffer_flags, true);
if (ret == buffer1_len)
ret = dvb_vb2_fill_buffer(&dmxdevfilter->vb2_ctx,
buffer2, buffer2_len,
- buffer_flags);
+ buffer_flags, true);
} else {
ret = dvb_dmxdev_buffer_write(&dmxdevfilter->buffer,
buffer1, buffer1_len);
@@ -452,10 +452,10 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len,

if (dvb_vb2_is_streaming(ctx)) {
ret = dvb_vb2_fill_buffer(ctx, buffer1, buffer1_len,
- buffer_flags);
+ buffer_flags, false);
if (ret == buffer1_len)
ret = dvb_vb2_fill_buffer(ctx, buffer2, buffer2_len,
- buffer_flags);
+ buffer_flags, false);
} else {
if (buffer->error) {
spin_unlock(&dmxdevfilter->dev->lock);
diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c
index 29edaaff7a5c9..7444bbc2f24d9 100644
--- a/drivers/media/dvb-core/dvb_vb2.c
+++ b/drivers/media/dvb-core/dvb_vb2.c
@@ -249,7 +249,8 @@ int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx)

int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
const unsigned char *src, int len,
- enum dmx_buffer_flags *buffer_flags)
+ enum dmx_buffer_flags *buffer_flags,
+ bool flush)
{
unsigned long flags = 0;
void *vbuf = NULL;
@@ -306,7 +307,7 @@ int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
}
}

- if (ctx->nonblocking && ctx->buf) {
+ if (flush && ctx->buf) {
vb2_set_plane_payload(&ctx->buf->vb, 0, ll);
vb2_buffer_done(&ctx->buf->vb, VB2_BUF_STATE_DONE);
list_del(&ctx->buf->list);
diff --git a/include/media/dvb_vb2.h b/include/media/dvb_vb2.h
index 8cb88452cd6c2..0fbbfc65157e6 100644
--- a/include/media/dvb_vb2.h
+++ b/include/media/dvb_vb2.h
@@ -124,7 +124,7 @@ static inline int dvb_vb2_release(struct dvb_vb2_ctx *ctx)
return 0;
};
#define dvb_vb2_is_streaming(ctx) (0)
-#define dvb_vb2_fill_buffer(ctx, file, wait, flags) (0)
+#define dvb_vb2_fill_buffer(ctx, file, wait, flags, flush) (0)

static inline __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx,
struct file *file,
@@ -166,10 +166,12 @@ int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx);
* @buffer_flags:
* pointer to buffer flags as defined by &enum dmx_buffer_flags.
* can be NULL.
+ * @flush: flush the buffer, even if it isn't full.
*/
int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
const unsigned char *src, int len,
- enum dmx_buffer_flags *buffer_flags);
+ enum dmx_buffer_flags *buffer_flags,
+ bool flush);

/**
* dvb_vb2_poll - Wrapper to vb2_core_streamon() for Digital TV
--
2.51.0