Re: [PATCH] drm/tidss: Add MIT license along with GPL-2.0

[Devarsh Thakkar <devarsht@ti.com>]

Hi Laurent,

Thanks for the quick review.

On 13/09/24 13:54, Laurent Pinchart wrote:
> Hi Devarsh,
> 
> On Thu, Sep 12, 2024 at 10:41:42PM +0530, Devarsh Thakkar wrote:
>> Modify license to include dual licensing as GPL-2.0-only OR MIT license for
>> tidss display driver. This allows other operating system ecosystems such as
>> Zephyr and also the commercial firmwares to refer and derive code from this
> 
> GPL-2.0 isn't incompatible with "commercial". I think you mean
> "proprietary" here.
> 

Yes, GPL-2.0 is not incompatible to commercial but there is an enforecement
that derivative code needs to be GPL-2.0 licensed which may not fit well for
projects which are not using GPL-2.0 license. But yes MIT will also help
proprietary code, so I agree it is good to mention the same in commit message.

>> display driver in a more permissive manner.
> 
> How do you envision that to work ? Zephyr doesn't have KMS, so you can't
> use the driver as-is. What exactly would TI want to use from the Linux
> kernel driver ?
> 

Not the DRM/KMS part, but the tidss specific display controller programming is
the main point of interest. For e.g. At this point, mostly I see that the TI
customers are interested to re-use/derive code from u-boot tidss driver [1]
which is quite simple and use it in their test application or RTOS based
offerring which is non-GPL code. Since their test application has much more
code apart from the display part, which is non-GPL, they can't use GPL license.

Now since the u-boot tidss driver is derived from kernel tidss driver, my
understanding was that we need to change the license of kernel tidss driver
first before changing the u-boot tidss driver.

> Personally, there's a reason why I contribute code to the kernel under
> the GPL-2.0 license, it is to make sure the code will remain open. While
> I can accept other licenses on a case-by-case basis, I don't like the
> casual approach of this patch that seem (to me) to imply that the
> license is a mere detail. For a start I would like to know what
> "commercial firmwares" you're thinking about.
> 

Understood, let me know if above information suffice or any further
information is needed.

[1]:
https://gitlab.com/u-boot/u-boot/-/blob/master/drivers/video/tidss/tidss_drv.c?ref_type=heads

Regards
Devarsh