This is something that I've been thinking about for a while. We had a
discussion at LPC 2020 about this[1] but the proposals suggested there
never materialised.
In short, it is quite difficult for userspace to detect the feature
capability of syscalls at runtime. This is something a lot of programs
want to do, but they are forced to create elaborate scenarios to try to
figure out if a feature is supported without causing damage to the
system. For the vast majority of cases, each individual feature also
needs to be tested individually (because syscall results are
all-or-nothing), so testing even a single syscall's feature set can
easily inflate the startup time of programs.
This patchset implements the fairly minimal design I proposed in this
talk[2] and in some old LKML threads (though I can't find the exact
references ATM). The general flow looks like:
1. Userspace will indicate to the kernel that a syscall should a be
no-op by setting the top bit of the extensible struct size argument.
We will almost certainly never support exabyte sized structs, so the
top bits are free for us to use as makeshift flag bits. This is
preferable to using the per-syscall flag field inside the structure
because seccomp can easily detect the bit in the flag and allow the
probe or forcefully return -EEXTSYS_NOOP.
2. The kernel will then fill the provided structure with every valid
bit pattern that the current kernel understands.
For flags or other bitflag-like fields, this is the set of valid
flags or bits. For pointer fields or fields that take an arbitrary
value, the field has every bit set (0xFF... to fill the field) to
indicate that any value is valid in the field.
3. The syscall then returns -EEXTSYS_NOOP which is an errno that will
only ever be used for this purpose (so userspace can be sure that
the request succeeded).
On older kernels, the syscall will return a different error (usually
-E2BIG or -EFAULT) and userspace can do their old-fashioned checks.
4. Userspace can then check which flags and fields are supported by
looking at the fields in the returned structure. Flags are checked
by doing an AND with the flags field, and field support can checked
by comparing to 0. In principle you could just AND the entire
structure if you wanted to do this check generically without caring
about the structure contents (this is what libraries might consider
doing).
Userspace can even find out the internal kernel structure size by
passing a PAGE_SIZE buffer and seeing how many bytes are non-zero.
As with copy_struct_from_user(), this is designed to be forward- and
backwards- compatible.
This allows programas to get a one-shot understanding of what features a
syscall supports without having to do any elaborate setups or tricks to
detect support for destructive features. Flags can simply be ANDed to
check if they are in the supported set, and fields can just be checked
to see if they are non-zero.
This patchset is IMHO the simplest way we can add the ability to
introspect the feature set of extensible struct (copy_struct_from_user)
syscalls. It doesn't preclude the chance of a more generic mechanism
being added later.
The intended way of using this interface to get feature information
looks something like the following (imagine that openat2 has gained a
new field and a new flag in the future):
static bool openat2_no_automount_supported;
static bool openat2_cwd_fd_supported;
int check_openat2_support(void)
{
int err;
struct open_how how = {};
err = openat2(AT_FDCWD, ".", &how, CHECK_FIELDS | sizeof(how));
assert(err < 0);
switch (errno) {
case EFAULT: case E2BIG:
/* Old kernel... */
check_support_the_old_way();
break;
case EEXTSYS_NOOP:
openat2_no_automount_supported = (how.flags & RESOLVE_NO_AUTOMOUNT);
openat2_cwd_fd_supported = (how.cwd_fd != 0);
break;
}
}
This series adds CHECK_FIELDS support for the following extensible
struct syscalls, as they are quite likely to grow flags in the near
future:
* openat2
* clone3
* mount_setattr
[1]: https://lwn.net/Articles/830666/
[2]: https://youtu.be/ggD-eb3yPVs
Signed-off-by: Aleksa Sarai <cyphar(a)cyphar.com>
---
Changes in v2:
- Add CHECK_FIELDS support to mount_setattr(2).
- Fix build failure on architectures with custom errno values.
- Rework selftests to use the tools/ uAPI headers rather than custom
defining EEXTSYS_NOOP.
- Make sure we return -EINVAL and -E2BIG for invalid sizes even if
CHECK_FIELDS is set, and add some tests for that.
- v1: <https://lore.kernel.org/r/20240902-extensible-structs-check_fields-v1-0-545…>
---
Aleksa Sarai (10):
uaccess: add copy_struct_to_user helper
sched_getattr: port to copy_struct_to_user
openat2: explicitly return -E2BIG for (usize > PAGE_SIZE)
openat2: add CHECK_FIELDS flag to usize argument
selftests: openat2: add 0xFF poisoned data after misaligned struct
selftests: openat2: add CHECK_FIELDS selftests
clone3: add CHECK_FIELDS flag to usize argument
selftests: clone3: add CHECK_FIELDS selftests
mount_setattr: add CHECK_FIELDS flag to usize argument
selftests: mount_setattr: add CHECK_FIELDS selftest
arch/alpha/include/uapi/asm/errno.h | 3 +
arch/mips/include/uapi/asm/errno.h | 3 +
arch/parisc/include/uapi/asm/errno.h | 3 +
arch/sparc/include/uapi/asm/errno.h | 3 +
fs/namespace.c | 17 ++
fs/open.c | 18 ++
include/linux/uaccess.h | 98 ++++++++
include/uapi/asm-generic/errno.h | 3 +
include/uapi/linux/openat2.h | 2 +
kernel/fork.c | 30 ++-
kernel/sched/syscalls.c | 42 +---
tools/arch/alpha/include/uapi/asm/errno.h | 3 +
tools/arch/mips/include/uapi/asm/errno.h | 3 +
tools/arch/parisc/include/uapi/asm/errno.h | 3 +
tools/arch/sparc/include/uapi/asm/errno.h | 3 +
tools/include/uapi/asm-generic/errno.h | 3 +
tools/include/uapi/asm-generic/posix_types.h | 101 ++++++++
tools/testing/selftests/clone3/.gitignore | 1 +
tools/testing/selftests/clone3/Makefile | 4 +-
.../testing/selftests/clone3/clone3_check_fields.c | 264 +++++++++++++++++++++
tools/testing/selftests/mount_setattr/Makefile | 2 +-
.../selftests/mount_setattr/mount_setattr_test.c | 53 ++++-
tools/testing/selftests/openat2/Makefile | 2 +
tools/testing/selftests/openat2/openat2_test.c | 165 ++++++++++++-
24 files changed, 778 insertions(+), 51 deletions(-)
---
base-commit: 431c1646e1f86b949fa3685efc50b660a364c2b6
change-id: 20240803-extensible-structs-check_fields-a47e94cef691
Best regards,
--
Aleksa Sarai <cyphar(a)cyphar.com>
From: Zijun Hu <quic_zijuhu(a)quicinc.com>
It is bad for current match_free_decoder()'s logic to find a free switch
cxl decoder as explained below:
- If all child decoders are sorted by ID in ascending order, then
current logic can be simplified as below one:
static int match_free_decoder(struct device *dev, void *data)
{
struct cxl_decoder *cxld;
if (!is_switch_decoder(dev))
return 0;
cxld = to_cxl_decoder(dev);
return cxld->region ? 0 : 1;
}
dev = device_find_child(&port->dev, NULL, match_free_decoder);
which does not also need to modify device_find_child()'s match data.
- If all child decoders are NOT sorted by ID in ascending order, then
current logic are wrong as explained below:
F: free, (cxld->region == NULL) B: busy, (cxld->region != NULL)
S(n)F : State of switch cxl_decoder with ID n is Free
S(n)B : State of switch cxl_decoder with ID n is Busy
Provided there are 2 child decoders: S(1)F -> S(0)B, then current logic
will fail to find a free decoder even if there are a free one with ID 1
Anyway, current logic is not good, fixed by finding a free switch cxl
decoder with minimal ID.
Fixes: 384e624bb211 ("cxl/region: Attach endpoint decoders")
Closes: https://lore.kernel.org/all/cdfc6f98-1aa0-4cb5-bd7d-93256552c39b@icloud.com/
Cc: stable(a)vger.kernel.org
Signed-off-by: Zijun Hu <quic_zijuhu(a)quicinc.com>
---
Changes in v2:
- Correct title and commit message
- Link to v1: https://lore.kernel.org/r/20240903-fix_cxld-v1-1-61acba7198ae@quicinc.com
---
drivers/cxl/core/region.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 21ad5f242875..b9607b4fc40b 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -797,21 +797,26 @@ static size_t show_targetN(struct cxl_region *cxlr, char *buf, int pos)
static int match_free_decoder(struct device *dev, void *data)
{
struct cxl_decoder *cxld;
- int *id = data;
+ struct cxl_decoder *target_cxld;
+ struct device **target_device = data;
if (!is_switch_decoder(dev))
return 0;
cxld = to_cxl_decoder(dev);
-
- /* enforce ordered allocation */
- if (cxld->id != *id)
+ if (cxld->region)
return 0;
- if (!cxld->region)
- return 1;
-
- (*id)++;
+ if (!*target_device) {
+ *target_device = get_device(dev);
+ return 0;
+ }
+ /* enforce ordered allocation */
+ target_cxld = to_cxl_decoder(*target_device);
+ if (cxld->id < target_cxld->id) {
+ put_device(*target_device);
+ *target_device = get_device(dev);
+ }
return 0;
}
@@ -839,8 +844,7 @@ cxl_region_find_decoder(struct cxl_port *port,
struct cxl_endpoint_decoder *cxled,
struct cxl_region *cxlr)
{
- struct device *dev;
- int id = 0;
+ struct device *dev = NULL;
if (port == cxled_to_port(cxled))
return &cxled->cxld;
@@ -849,7 +853,8 @@ cxl_region_find_decoder(struct cxl_port *port,
dev = device_find_child(&port->dev, &cxlr->params,
match_auto_decoder);
else
- dev = device_find_child(&port->dev, &id, match_free_decoder);
+ /* Need to put_device(@dev) after use */
+ device_for_each_child(&port->dev, &dev, match_free_decoder);
if (!dev)
return NULL;
/*
---
base-commit: 67784a74e258a467225f0e68335df77acd67b7ab
change-id: 20240903-fix_cxld-4f6575a90619
Best regards,
--
Zijun Hu <quic_zijuhu(a)quicinc.com>
Backporting the sanity checks on pipes seems like a good idea. These
are basically the same as Takashi Iwai's patches upstream. The
difference is that upstream added two sanity checks to code that
doesn't exist in 4.19.
I had talked about backporting fcc2cc1f3561 ("USB: move
snd_usb_pipe_sanity_check into the USB core") but that's just a
refactor and not a bug fix.
Hillf Danton (1):
ALSA: usb-audio: Fix gpf in snd_usb_pipe_sanity_check
Takashi Iwai (1):
ALSA: usb-audio: Sanity checks for each pipe and EP types
sound/usb/helper.c | 17 +++++++++++++++++
sound/usb/helper.h | 1 +
sound/usb/quirks.c | 14 +++++++++++---
3 files changed, 29 insertions(+), 3 deletions(-)
--
2.45.2
We have met a deadlock issue on our device which use 5.15.y when resuming.
After applying this patch which is picked from mainline, issue solved.
Backport to 6.6.y also.
Rafael J. Wysocki (1):
PM: sleep: Restore asynchronous device resume optimization
drivers/base/power/main.c | 117 +++++++++++++++++++++-----------------
include/linux/pm.h | 1 +
2 files changed, 65 insertions(+), 53 deletions(-)
--
2.18.0
The Qualcomm serial console implementation is broken and can lose
characters when the serial port is also used for tty output.
Specifically, the console code only waits for the current tx command to
complete when all data has already been written to the fifo. When there
are on-going longer transfers this often means that console output is
lost when the console code inadvertently "hijacks" the current tx
command instead of starting a new one.
This can, for example, be observed during boot when console output that
should have been interspersed with init output is truncated:
[ 9.462317] qcom-snps-eusb2-hsphy fde000.phy: Registered Qcom-eUSB2 phy
[ OK ] Found device KBG50ZNS256G KIOXIA Wi[ 9.471743ndows.
[ 9.539915] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
Add a new state variable to track how much data has been written to the
fifo and use it to determine when the fifo and shift register are both
empty. This is needed since there is currently no other known way to
determine when the shift register is empty.
This in turn allows the console code to interrupt long transfers without
losing data.
Note that the oops-in-progress case is similarly broken as it does not
cancel any active command and also waits for the wrong status flag when
attempting to drain the fifo (TX_FIFO_NOT_EMPTY_EN is only set when
cancelling a command leaves data in the fifo).
Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Fixes: a1fee899e5be ("tty: serial: qcom_geni_serial: Fix softlock")
Fixes: 9e957a155005 ("serial: qcom-geni: Don't cancel/abort if we can't get the port lock")
Cc: stable(a)vger.kernel.org # 4.17
Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org>
---
drivers/tty/serial/qcom_geni_serial.c | 48 ++++++++++++++-------------
1 file changed, 25 insertions(+), 23 deletions(-)
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 7029c39a9a21..be620c5703f5 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -131,6 +131,7 @@ struct qcom_geni_serial_port {
bool brk;
unsigned int tx_remaining;
+ unsigned int tx_queued;
int wakeup_irq;
bool rx_tx_swap;
bool cts_rts_swap;
@@ -144,6 +145,8 @@ static const struct uart_ops qcom_geni_uart_pops;
static struct uart_driver qcom_geni_console_driver;
static struct uart_driver qcom_geni_uart_driver;
+static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport);
+
static inline struct qcom_geni_serial_port *to_dev_port(struct uart_port *uport)
{
return container_of(uport, struct qcom_geni_serial_port, uport);
@@ -308,6 +311,17 @@ static bool qcom_geni_serial_poll_bit(struct uart_port *uport,
return qcom_geni_serial_poll_bitfield(uport, offset, field, set ? field : 0);
}
+static void qcom_geni_serial_drain_fifo(struct uart_port *uport)
+{
+ struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+ if (!qcom_geni_serial_main_active(uport))
+ return;
+
+ qcom_geni_serial_poll_bitfield(uport, SE_GENI_M_GP_LENGTH, GP_LENGTH,
+ port->tx_queued);
+}
+
static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size)
{
u32 m_cmd;
@@ -476,7 +490,6 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s,
struct qcom_geni_serial_port *port;
bool locked = true;
unsigned long flags;
- u32 geni_status;
WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS);
@@ -490,34 +503,20 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s,
else
uart_port_lock_irqsave(uport, &flags);
- geni_status = readl(uport->membase + SE_GENI_STATUS);
+ if (qcom_geni_serial_main_active(uport)) {
+ /* Wait for completion or drain FIFO */
+ if (!locked || port->tx_remaining == 0)
+ qcom_geni_serial_poll_tx_done(uport);
+ else
+ qcom_geni_serial_drain_fifo(uport);
- if (!locked) {
- /*
- * We can only get here if an oops is in progress then we were
- * unable to get the lock. This means we can't safely access
- * our state variables like tx_remaining. About the best we
- * can do is wait for the FIFO to be empty before we start our
- * transfer, so we'll do that.
- */
- qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
- M_TX_FIFO_NOT_EMPTY_EN, false);
- } else if ((geni_status & M_GENI_CMD_ACTIVE) && !port->tx_remaining) {
- /*
- * It seems we can't interrupt existing transfers if all data
- * has been sent, in which case we need to look for done first.
- */
- qcom_geni_serial_poll_tx_done(uport);
+ qcom_geni_serial_cancel_tx_cmd(uport);
}
__qcom_geni_serial_console_write(uport, s, count);
-
- if (locked) {
- if (port->tx_remaining)
- qcom_geni_serial_setup_tx(uport, port->tx_remaining);
+ if (locked)
uart_port_unlock_irqrestore(uport, flags);
- }
}
static void handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
@@ -698,6 +697,7 @@ static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport)
writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
port->tx_remaining = 0;
+ port->tx_queued = 0;
}
static void qcom_geni_serial_handle_rx_fifo(struct uart_port *uport, bool drop)
@@ -924,6 +924,7 @@ static void qcom_geni_serial_handle_tx_fifo(struct uart_port *uport,
if (!port->tx_remaining) {
qcom_geni_serial_setup_tx(uport, pending);
port->tx_remaining = pending;
+ port->tx_queued = 0;
irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
@@ -932,6 +933,7 @@ static void qcom_geni_serial_handle_tx_fifo(struct uart_port *uport,
}
qcom_geni_serial_send_chunk_fifo(uport, chunk);
+ port->tx_queued += chunk;
/*
* The tx fifo watermark is level triggered and latched. Though we had
--
2.44.2
This is an automatic generated email to let you know that the following patch were queued:
Subject: media: qcom: camss: Fix ordering of pm_runtime_enable
Author: Bryan O'Donoghue <bryan.odonoghue(a)linaro.org>
Date: Mon Jul 29 13:42:03 2024 +0100
pm_runtime_enable() should happen prior to vfe_get() since vfe_get() calls
pm_runtime_resume_and_get().
This is a basic race condition that doesn't show up for most users so is
not widely reported. If you blacklist qcom-camss in modules.d and then
subsequently modprobe the module post-boot it is possible to reliably show
this error up.
The kernel log for this error looks like this:
qcom-camss ac5a000.camss: Failed to power up pipeline: -13
Fixes: 02afa816dbbf ("media: camss: Add basic runtime PM support")
Reported-by: Johan Hovold <johan+linaro(a)kernel.org>
Closes: https://lore.kernel.org/lkml/ZoVNHOTI0PKMNt4_@hovoldconsulting.com/
Tested-by: Johan Hovold <johan+linaro(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue(a)linaro.org>
Reviewed-by: Konrad Dybcio <konradybcio(a)kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco(a)xs4all.nl>
drivers/media/platform/qcom/camss/camss.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
index 51b1d3550421..d64985ca6e88 100644
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -2283,6 +2283,8 @@ static int camss_probe(struct platform_device *pdev)
v4l2_async_nf_init(&camss->notifier, &camss->v4l2_dev);
+ pm_runtime_enable(dev);
+
num_subdevs = camss_of_parse_ports(camss);
if (num_subdevs < 0) {
ret = num_subdevs;
@@ -2323,8 +2325,6 @@ static int camss_probe(struct platform_device *pdev)
}
}
- pm_runtime_enable(dev);
-
return 0;
err_register_subdevs:
@@ -2332,6 +2332,7 @@ err_register_subdevs:
err_v4l2_device_unregister:
v4l2_device_unregister(&camss->v4l2_dev);
v4l2_async_nf_cleanup(&camss->notifier);
+ pm_runtime_disable(dev);
err_genpd_cleanup:
camss_genpd_cleanup(camss);
This is an automatic generated email to let you know that the following patch were queued:
Subject: media: qcom: camss: Remove use_count guard in stop_streaming
Author: Bryan O'Donoghue <bryan.odonoghue(a)linaro.org>
Date: Mon Jul 29 13:42:02 2024 +0100
The use_count check was introduced so that multiple concurrent Raw Data
Interfaces RDIs could be driven by different virtual channels VCs on the
CSIPHY input driving the video pipeline.
This is an invalid use of use_count though as use_count pertains to the
number of times a video entity has been opened by user-space not the number
of active streams.
If use_count and stream-on count don't agree then stop_streaming() will
break as is currently the case and has become apparent when using CAMSS
with libcamera's released softisp 0.3.
The use of use_count like this is a bit hacky and right now breaks regular
usage of CAMSS for a single stream case. Stopping qcam results in the splat
below, and then it cannot be started again and any attempts to do so fails
with -EBUSY.
[ 1265.509831] WARNING: CPU: 5 PID: 919 at drivers/media/common/videobuf2/videobuf2-core.c:2183 __vb2_queue_cancel+0x230/0x2c8 [videobuf2_common]
...
[ 1265.510630] Call trace:
[ 1265.510636] __vb2_queue_cancel+0x230/0x2c8 [videobuf2_common]
[ 1265.510648] vb2_core_streamoff+0x24/0xcc [videobuf2_common]
[ 1265.510660] vb2_ioctl_streamoff+0x5c/0xa8 [videobuf2_v4l2]
[ 1265.510673] v4l_streamoff+0x24/0x30 [videodev]
[ 1265.510707] __video_do_ioctl+0x190/0x3f4 [videodev]
[ 1265.510732] video_usercopy+0x304/0x8c4 [videodev]
[ 1265.510757] video_ioctl2+0x18/0x34 [videodev]
[ 1265.510782] v4l2_ioctl+0x40/0x60 [videodev]
...
[ 1265.510944] videobuf2_common: driver bug: stop_streaming operation is leaving buffer 0 in active state
[ 1265.511175] videobuf2_common: driver bug: stop_streaming operation is leaving buffer 1 in active state
[ 1265.511398] videobuf2_common: driver bug: stop_streaming operation is leaving buffer 2 in active st
One CAMSS specific way to handle multiple VCs on the same RDI might be:
- Reference count each pipeline enable for CSIPHY, CSID, VFE and RDIx.
- The video buffers are already associated with msm_vfeN_rdiX so
release video buffers when told to do so by stop_streaming.
- Only release the power-domains for the CSIPHY, CSID and VFE when
their internal refcounts drop.
Either way refusing to release video buffers based on use_count is
erroneous and should be reverted. The silicon enabling code for selecting
VCs is perfectly fine. Its a "known missing feature" that concurrent VCs
won't work with CAMSS right now.
Initial testing with this code didn't show an error but, SoftISP and "real"
usage with Google Hangouts breaks the upstream code pretty quickly, we need
to do a partial revert and take another pass at VCs.
This commit partially reverts commit 89013969e232 ("media: camss: sm8250:
Pipeline starting and stopping for multiple virtual channels")
Fixes: 89013969e232 ("media: camss: sm8250: Pipeline starting and stopping for multiple virtual channels")
Reported-by: Johan Hovold <johan+linaro(a)kernel.org>
Closes: https://lore.kernel.org/lkml/ZoVNHOTI0PKMNt4_@hovoldconsulting.com/
Tested-by: Johan Hovold <johan+linaro(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue(a)linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco(a)xs4all.nl>
drivers/media/platform/qcom/camss/camss-video.c | 6 ------
1 file changed, 6 deletions(-)
---
diff --git a/drivers/media/platform/qcom/camss/camss-video.c b/drivers/media/platform/qcom/camss/camss-video.c
index cd72feca618c..3b8fc31d957c 100644
--- a/drivers/media/platform/qcom/camss/camss-video.c
+++ b/drivers/media/platform/qcom/camss/camss-video.c
@@ -297,12 +297,6 @@ static void video_stop_streaming(struct vb2_queue *q)
ret = v4l2_subdev_call(subdev, video, s_stream, 0);
- if (entity->use_count > 1) {
- /* Don't stop if other instances of the pipeline are still running */
- dev_dbg(video->camss->dev, "Video pipeline still used, don't stop streaming.\n");
- return;
- }
-
if (ret) {
dev_err(video->camss->dev, "Video pipeline stop failed: %d\n", ret);
return;