Removal of V4L1 drivers

Removal of V4L1 drivers

[Hans Verkuil]

Hi Hans, Mauro,

The se401, vicam, ibmcam and konicawc drivers are the only V4L1 drivers left in
2.6.37. The others are either converted or moved to staging (stradis and cpia),
ready to be removed.

Hans, what is the status of those four drivers? How likely is it that they will be
converted to V4L2?

If we can't convert them to V4L2 for 2.6.38, then we can at least remove the
V4L1_COMPAT code throughout the v4l drivers and move those four drivers to staging.

For 2.6.39 we either remove them or when they are converted to V4L2 they are moved
out of staging again (probably to gspca).

As an illustration I have removed the V4L1_COMPAT mode in this branch:

http://git.linuxtv.org/hverkuil/media_tree.git?a=shortlog;h=refs/heads/v4l1

There are two drivers that need more work: stk-webcam has some controls under sysfs
that are enabled when CONFIG_VIDEO_V4L1_COMPAT is set. These controls should be
rewritten as V4L2 controls. Hans, didn't you have hardware to test this driver?
I should be able to make a patch that you can test.

The other driver is the zoran driver which has a bunch of zoran-specific ioctls
under CONFIG_VIDEO_V4L1_COMPAT. I think I can just delete the lot since they are
all replaced by V4L2 counterparts AFAIK. But it would be good if someone else can
also take a look at that.

Regards,

	Hans

-- 
Hans Verkuil - video4linux developer - sponsored by Cisco

Re: Removal of V4L1 drivers

[Hans de Goede]

Hi,

On 12/24/2010 02:42 PM, Hans Verkuil wrote:
> Hi Hans, Mauro,
>
> The se401, vicam, ibmcam and konicawc drivers are the only V4L1 drivers left in
> 2.6.37. The others are either converted or moved to staging (stradis and cpia),
> ready to be removed.
>
> Hans, what is the status of those four drivers?

se401:
I have hardware I have taken a look at the driver, converting it is a bit
of a pain because it uses a really ugly written statefull decompressor inside
the kernel code. The cameras have an uncompressed mode too. I can start doing
a conversion to / rewrite as gspca subdriver supporting only the uncompressed
mode for now:

vicam:
Devin Heitmueller (added to the CC) has one such a camera, which he still needs
to get into my hands, once I have it I can convert the driver.

ibmcam and konicawc:
Both drivers were converted by me recently and the new gspca subdrivers for these
have been pulled by Mauro for 2.6.37 .

<snip>

> There are two drivers that need more work: stk-webcam has some controls under sysfs
> that are enabled when CONFIG_VIDEO_V4L1_COMPAT is set. These controls should be
> rewritten as V4L2 controls. Hans, didn't you have hardware to test this driver?

No I don't have any Syntek DC1125 based webcams.

<snip>

Regards,

Hans

Re: Removal of V4L1 drivers

[Hans Verkuil]

On Friday, December 24, 2010 15:47:57 Hans de Goede wrote:
> Hi,
> 
> On 12/24/2010 02:42 PM, Hans Verkuil wrote:
> > Hi Hans, Mauro,
> >
> > The se401, vicam, ibmcam and konicawc drivers are the only V4L1 drivers left in
> > 2.6.37. The others are either converted or moved to staging (stradis and cpia),
> > ready to be removed.
> >
> > Hans, what is the status of those four drivers?
> 
> se401:
> I have hardware I have taken a look at the driver, converting it is a bit
> of a pain because it uses a really ugly written statefull decompressor inside
> the kernel code. The cameras have an uncompressed mode too. I can start doing
> a conversion to / rewrite as gspca subdriver supporting only the uncompressed
> mode for now:
> 
> vicam:
> Devin Heitmueller (added to the CC) has one such a camera, which he still needs
> to get into my hands, once I have it I can convert the driver.

I think these two should be moved to staging for 2.6.38. And either removed or
converted for 2.6.39.

> ibmcam and konicawc:
> Both drivers were converted by me recently and the new gspca subdrivers for these
> have been pulled by Mauro for 2.6.37 .

So these two can be removed in 2.6.38, right?

Regards,

	Hans

-- 
Hans Verkuil - video4linux developer - sponsored by Cisco

Re: Removal of V4L1 drivers

[Hans de Goede]

Hi,

On 12/24/2010 07:58 PM, Hans Verkuil wrote:
> On Friday, December 24, 2010 15:47:57 Hans de Goede wrote:
>> Hi,
>>
>> On 12/24/2010 02:42 PM, Hans Verkuil wrote:
>>> Hi Hans, Mauro,
>>>
>>> The se401, vicam, ibmcam and konicawc drivers are the only V4L1 drivers left in
>>> 2.6.37. The others are either converted or moved to staging (stradis and cpia),
>>> ready to be removed.
>>>
>>> Hans, what is the status of those four drivers?
>>
>> se401:
>> I have hardware I have taken a look at the driver, converting it is a bit
>> of a pain because it uses a really ugly written statefull decompressor inside
>> the kernel code. The cameras have an uncompressed mode too. I can start doing
>> a conversion to / rewrite as gspca subdriver supporting only the uncompressed
>> mode for now:
>>
>> vicam:
>> Devin Heitmueller (added to the CC) has one such a camera, which he still needs
>> to get into my hands, once I have it I can convert the driver.
>
> I think these two should be moved to staging for 2.6.38. And either removed or
> converted for 2.6.39.
>

Ok.

>> ibmcam and konicawc:
>> Both drivers were converted by me recently and the new gspca subdrivers for these
>> have been pulled by Mauro for 2.6.37 .
>
> So these two can be removed in 2.6.38, right?

Right.

Regards,

Hans

Re: Removal of V4L1 drivers

[Mauro Carvalho Chehab]

Em 24-12-2010 11:42, Hans Verkuil escreveu:
> Hi Hans, Mauro,
> 
> The se401, vicam, ibmcam and konicawc drivers are the only V4L1 drivers left in
> 2.6.37. The others are either converted or moved to staging (stradis and cpia),
> ready to be removed.
> 
> Hans, what is the status of those four drivers? How likely is it that they will be
> converted to V4L2?
> 
> If we can't convert them to V4L2 for 2.6.38, then we can at least remove the
> V4L1_COMPAT code throughout the v4l drivers and move those four drivers to staging.
> 
> For 2.6.39 we either remove them or when they are converted to V4L2 they are moved
> out of staging again (probably to gspca).
> 
> As an illustration I have removed the V4L1_COMPAT mode in this branch:
> 
> http://git.linuxtv.org/hverkuil/media_tree.git?a=shortlog;h=refs/heads/v4l1

Seems ok for me.

> 
> There are two drivers that need more work: stk-webcam has some controls under sysfs
> that are enabled when CONFIG_VIDEO_V4L1_COMPAT is set. These controls should be
> rewritten as V4L2 controls. Hans, didn't you have hardware to test this driver?
> I should be able to make a patch that you can test.

The conversion seems trivial. Even knowing that none of us have that hardware, I think
we should just convert it and apply the patch. We'll have the entire .38 kernel cycle for
people to test.

> The other driver is the zoran driver which has a bunch of zoran-specific ioctls
> under CONFIG_VIDEO_V4L1_COMPAT. I think I can just delete the lot since they are
> all replaced by V4L2 counterparts AFAIK. But it would be good if someone else can
> also take a look at that.

They seem to mimic v4l2. Also, they implement their own private API, and this is a bad
thing. I doubt that most applications would use that API. So, if the driver works fine
with just V4L2, I think it is ok to just remove that old code. So let's go ahead and 
remove, asking people to test it. I'll do some tests also in Jan.

Cheers,
Mauro

Re: Removal of V4L1 drivers

[Mauro Carvalho Chehab]

Em 24-12-2010 12:47, Hans de Goede escreveu:
> Hi,
> 
> On 12/24/2010 02:42 PM, Hans Verkuil wrote:
>> Hi Hans, Mauro,
>>
>> The se401, vicam, ibmcam and konicawc drivers are the only V4L1 drivers left in
>> 2.6.37. The others are either converted or moved to staging (stradis and cpia),
>> ready to be removed.
>>
>> Hans, what is the status of those four drivers?
> 
> se401:
> I have hardware I have taken a look at the driver, converting it is a bit
> of a pain because it uses a really ugly written statefull decompressor inside
> the kernel code. The cameras have an uncompressed mode too. I can start doing
> a conversion to / rewrite as gspca subdriver supporting only the uncompressed
> mode for now:

Seems fine for me.

> vicam:
> Devin Heitmueller (added to the CC) has one such a camera, which he still needs
> to get into my hands, once I have it I can convert the driver.
> 
> ibmcam and konicawc:
> Both drivers were converted by me recently and the new gspca subdrivers for these
> have been pulled by Mauro for 2.6.37 .
> 
> <snip>
> 
>> There are two drivers that need more work: stk-webcam has some controls under sysfs
>> that are enabled when CONFIG_VIDEO_V4L1_COMPAT is set. These controls should be
>> rewritten as V4L2 controls. Hans, didn't you have hardware to test this driver?
> 
> No I don't have any Syntek DC1125 based webcams.

The three controls there seem trivial to be ported to the standard API. So, let's 
just do the patch and apply, asking the community to test.

Cheers,
Mauro

Re: Removal of V4L1 drivers

[Mauro Carvalho Chehab]

Em 24-12-2010 17:55, Hans de Goede escreveu:
> Hi,
> 
> On 12/24/2010 07:58 PM, Hans Verkuil wrote:
>> On Friday, December 24, 2010 15:47:57 Hans de Goede wrote:
>>> Hi,
>>>
>>> On 12/24/2010 02:42 PM, Hans Verkuil wrote:
>>>> Hi Hans, Mauro,
>>>>
>>>> The se401, vicam, ibmcam and konicawc drivers are the only V4L1 drivers left in
>>>> 2.6.37. The others are either converted or moved to staging (stradis and cpia),
>>>> ready to be removed.
>>>>
>>>> Hans, what is the status of those four drivers?
>>>
>>> se401:
>>> I have hardware I have taken a look at the driver, converting it is a bit
>>> of a pain because it uses a really ugly written statefull decompressor inside
>>> the kernel code. The cameras have an uncompressed mode too. I can start doing
>>> a conversion to / rewrite as gspca subdriver supporting only the uncompressed
>>> mode for now:
>>>
>>> vicam:
>>> Devin Heitmueller (added to the CC) has one such a camera, which he still needs
>>> to get into my hands, once I have it I can convert the driver.
>>
>> I think these two should be moved to staging for 2.6.38. And either removed or
>> converted for 2.6.39.
>>
> 
> Ok.
> 
>>> ibmcam and konicawc:
>>> Both drivers were converted by me recently and the new gspca subdrivers for these
>>> have been pulled by Mauro for 2.6.37 .
>>
>> So these two can be removed in 2.6.38, right?
> 
> Right.


OK, moving them to staging seems the best way to do it. Please, add a comment at
Kconfig help that they use the legacy V4L1 API and may be removed from .39 if not
converted to V4L2. Of course, the README file will also say that, maybe providing
more details.

Cheers,
Mauro.

Re: Removal of V4L1 drivers

[Hans Verkuil]

On Saturday, December 25, 2010 10:18:20 Mauro Carvalho Chehab wrote:
> Em 24-12-2010 17:55, Hans de Goede escreveu:
> > Hi,
> > 
> > On 12/24/2010 07:58 PM, Hans Verkuil wrote:
> >> On Friday, December 24, 2010 15:47:57 Hans de Goede wrote:
> >>> Hi,
> >>>
> >>> On 12/24/2010 02:42 PM, Hans Verkuil wrote:
> >>>> Hi Hans, Mauro,
> >>>>
> >>>> The se401, vicam, ibmcam and konicawc drivers are the only V4L1 drivers left in
> >>>> 2.6.37. The others are either converted or moved to staging (stradis and cpia),
> >>>> ready to be removed.
> >>>>
> >>>> Hans, what is the status of those four drivers?
> >>>
> >>> se401:
> >>> I have hardware I have taken a look at the driver, converting it is a bit
> >>> of a pain because it uses a really ugly written statefull decompressor inside
> >>> the kernel code. The cameras have an uncompressed mode too. I can start doing
> >>> a conversion to / rewrite as gspca subdriver supporting only the uncompressed
> >>> mode for now:
> >>>
> >>> vicam:
> >>> Devin Heitmueller (added to the CC) has one such a camera, which he still needs
> >>> to get into my hands, once I have it I can convert the driver.
> >>
> >> I think these two should be moved to staging for 2.6.38. And either removed or
> >> converted for 2.6.39.
> >>
> > 
> > Ok.
> > 
> >>> ibmcam and konicawc:
> >>> Both drivers were converted by me recently and the new gspca subdrivers for these
> >>> have been pulled by Mauro for 2.6.37 .
> >>
> >> So these two can be removed in 2.6.38, right?
> > 
> > Right.
> 
> 
> OK, moving them to staging seems the best way to do it. Please, add a comment at
> Kconfig help that they use the legacy V4L1 API and may be removed from .39 if not
> converted to V4L2. Of course, the README file will also say that, maybe providing
> more details.

Thanks for your input! I'll work on this in the next few days.

Regards,

	Hans

-- 
Hans Verkuil - video4linux developer - sponsored by Cisco