Hi Andre,
On 8/9/19 5:52 PM, André Almeida wrote:
Hello Shuah,
Thanks for the patch, I did some comments below.
On 8/9/19 6:45 PM, Shuah Khan wrote:
vimc uses Component API to split the driver into functional components.
The real hardware resembles a monolith structure than component and
component structure added a level of complexity making it hard to
maintain without adding any real benefit.
The sensor is one vimc component that would makes sense to be a separate
module to closely align with the real hardware. It would be easier to
collapse vimc into single monolithic driver first and then split the
sensor off as a separate module.
This patch series emoves the component API and makes minimal changes to
the code base preserving the functional division of the code structure.
Preserving the functional structure allows us to split the sensor off
as a separate module in the future.
Major design elements in this change are:
- Use existing struct vimc_ent_config and struct vimc_pipeline_config
to drive the initialization of the functional components.
- Make vimc_ent_config global by moving it to vimc.h
- Add two new hooks add and rm to initialize and register, unregister
and free subdevs.
- All component API is now gone and bind and unbind hooks are modified
to do "add" and "rm" with minimal changes to just add and rm subdevs.
- vimc-core's bind and unbind are now register and unregister.
- vimc-core invokes "add" hooks from its vimc_register_devices().
The "add" hooks remain the same and register subdevs. They don't
create platform devices of their own and use vimc's pdev.dev as
their reference device. The "add" hooks save their vimc_ent_device(s)
in the corresponding vimc_ent_config.
- vimc-core invokes "rm" hooks from its unregister to unregister subdevs
and cleanup.
- vimc-core invokes "add" and "rm" hooks with pointer to struct vimc_device
and the corresponding struct vimc_ent_config pointer.
The following configure and stream test works on all devices.
media-ctl -d platform:vimc -V '"Sensor A":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d platform:vimc -V '"Debayer A":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d platform:vimc -V '"Sensor B":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d platform:vimc -V '"Debayer B":0[fmt:SBGGR8_1X8/640x480]'
v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440
v4l2-ctl -z platform:vimc -d "Raw Capture 0" -v pixelformat=BA81
v4l2-ctl -z platform:vimc -d "Raw Capture 1" -v pixelformat=BA81
v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video1
v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video2
v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video3
The third patch in the series fixes a general protection fault found
when rmmod is done while stream is active.
I applied your patch on top of media_tree/master and I did some testing.
Not sure if I did something wrong, but just adding and removing the
module generated a kernel panic:
Thanks for testing.
Odd. I tested modprobe and rmmod both.I was working on Linux 5.3-rc2.
I will apply these to media latest and work from there. I have to
rebase these on top of the reverts from Lucas and Helen
~# modprobe vimc
~# rmmod vimc
[ 16.452974] stack segment: 0000 [#1] SMP PTI
[ 16.453688] CPU: 0 PID: 2038 Comm: rmmod Not tainted 5.3.0-rc2+ #36
[ 16.454678] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.12.0-20181126_142135-anatol 04/01/2014
[ 16.456191] RIP: 0010:kfree+0x4d/0x240
<registers values...>
[ 16.469188] Call Trace:
[ 16.469666] vimc_remove+0x35/0x90 [vimc]
[ 16.470436] platform_drv_remove+0x1f/0x40
[ 16.471233] device_release_driver_internal+0xd3/0x1b0
[ 16.472184] driver_detach+0x37/0x6b
[ 16.472882] bus_remove_driver+0x50/0xc1
[ 16.473569] vimc_exit+0xc/0xca0 [vimc]
[ 16.474231] __x64_sys_delete_module+0x18d/0x240
[ 16.475036] do_syscall_64+0x43/0x110
[ 16.475656] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 16.476504] RIP: 0033:0x7fceb8dafa4b
<registers values...>
[ 16.484853] Modules linked in: vimc(-) videobuf2_vmalloc
videobuf2_memops v4l2_tpg videobuf2_v4l2 videobuf2_common
[ 16.486187] ---[ end trace 91e5e0894e254d49 ]---
[ 16.486758] RIP: 0010:kfree+0x4d/0x240
<registers values...>
fish: “rmmod vimc” terminated by signal SIGSEGV (Address boundary error)
I just added the module after booting, no other action was made. Here is
how my `git log --oneline` looks like:
897d708e922b media: vimc: Fix gpf in rmmod path when stream is active
2e4a5ad8ad6d media: vimc: Collapse component structure into a single
monolithic driver
7c8da1687e92 media: vimc: move private defines to a common header
97299a303532 media: Remove dev_err() usage after platform_get_irq()
25a3d6bac6b9 media: adv7511/cobalt: rename driver name to adv7511-v4l2
...
vimc_print_dot (--print-dot) topology after this change:
digraph board {
rankdir=TB
n00000001 [label="{{} | Sensor A\n/dev/v4l-subdev0 | {<port0> 0}}", shape=Mrecord, style=filled, fillcolor=green]
n00000001:port0 -> n00000005:port0 [style=bold]
n00000001:port0 -> n0000000b [style=bold]
n00000003 [label="{{} | Sensor B\n/dev/v4l-subdev1 | {<port0> 0}}", shape=Mrecord, style=filled, fillcolor=green]
n00000003:port0 -> n00000008:port0 [style=bold]
n00000003:port0 -> n0000000f [style=bold]
n00000005 [label="{{<port0> 0} | Debayer A\n/dev/v4l-subdev2 | {<port1> 1}}", shape=Mrecord, style=filled, fillcolor=green]
n00000005:port1 -> n00000015:port0
n00000008 [label="{{<port0> 0} | Debayer B\n/dev/v4l-subdev3 | {<port1> 1}}", shape=Mrecord, style=filled, fillcolor=green]
n00000008:port1 -> n00000015:port0 [style=dashed]
n0000000b [label="Raw Capture 0\n/dev/video1", shape=box, style=filled, fillcolor=yellow]
n0000000f [label="Raw Capture 1\n/dev/video2", shape=box, style=filled, fillcolor=yellow]
n00000013 [label="{{} | RGB/YUV Input\n/dev/v4l-subdev4 | {<port0> 0}}", shape=Mrecord, style=filled, fillcolor=green]
n00000013:port0 -> n00000015:port0 [style=dashed]
n00000015 [label="{{<port0> 0} | Scaler\n/dev/v4l-subdev5 | {<port1> 1}}", shape=Mrecord, style=filled, fillcolor=green]
n00000015:port1 -> n00000018 [style=bold]
n00000018 [label="RGB/YUV Capture\n/dev/video3", shape=box, style=filled, fillcolor=yellow]
}
Since the topology changed, it would be nice to change in the
documentation as well. The current dot file can be found at
`Documentation/media/v4l-drivers/vimc.dot` and it's rendered at this
page: https://www.kernel.org/doc/html/latest/media/v4l-drivers/vimc.html
Topology shouldn't have changed. No changes to links or pads etc.
I will take a look to be sure. I agree that if topology changes
document should be updated.
thanks,
-- Shuah
