Re: [PATCH v3] fbdev/hga: Request memory region before ioremap

[Thomas Zimmermann <tzimmermann@suse.de>]

Hi

Am 13.03.26 um 13:50 schrieb Helge Deller:
> Hi Thomas,
>
> On 3/13/26 09:05, Thomas Zimmermann wrote:
>> Am 12.03.26 um 20:47 schrieb Helge Deller:
>>> On 3/12/26 16:10, Thomas Zimmermann wrote:
>>>> Am 12.03.26 um 16:04 schrieb Hardik Phalet:
>>>>> On Tue Mar 10, 2026 at 6:38 PM IST, Thomas Zimmermann wrote:
>>>>>> Hi,
>>>>>>
>>>>>> thanks for the patch. Let's hope there are no conflicts with other
>>>>>> hardware.  IDK if anyone still uses this driver.
>>>>> Hi Thomas,
>>>>>
>>>>> Thanks for reviewing this.
>>>>>
>>>>> Since I currently do not have access to the hardware needed to 
>>>>> test the
>>>>> change properly, I will drop this patch for now. I may revisit it 
>>>>> once I
>>>>> can validate the behavior on real hardware.
>>>>
>>>> Good luck. That's the Hercules framebuffer driver. Finding such
>>>> ancient hardware that can run modern Linux is nigh impossible.
>>>>
>>>> But we can merge the patch. If it breaks anyone's setup, they will 
>>>> send a bug report.
>>>>
>>>> Helge will pick up the fix if he's ok with it.
>>>
>>> No, I don't want to merge such patches any longer without any testing
>>> on real hardware. There is no actual problem (else someone would 
>>> have reported),
>>> as such I don't see a benefit to apply it. Applying it just brings 
>>> the risk
>>> that we break it for someone.
>>> So, NAK.
>>>
>>> I believe I wrote about my opinion already in another patch?
>>
>> Sorry, I wasn't aware.
>>
>>> I think we should rephrase that specific TODO item (which mentions 
>>> the memory
>>> region allocation) that only patches which have been tested are 
>>> accepted.
>>
>> There will likely no one show up here for testing unless it breaks
>> there system. Which you won't know until you merge the patch.
>
> No-one likes to merge unnecessary patches which highly potentially
> introduce malfunctioning and haven't been tested at all.
>
>> If only pre-tested patches can go in,
>
> You misunderstand.
> I'm still happy to take *any* patches for fbdev.
> Even untested ones if they
> a) seem necessary (e.g. bugfix), or
> b) seem beneficial (code cleanup)
> as long as they don't break the driver. This patch may break the driver.

Any patch falling under a) or b) may break a driver. The patch at hand 
isn't even particularly fragile. People keep posting clean-up patches 
for some of the fbdev drivers and I doubt that most of them have seen 
any testing.

My point here is that if a patch breaks the driver then someone will 
show up and report the regression. If you operate under the (implicit) 
assumption that the driver breaks without anyone reporting the 
regression, the corollary is that the driver is unused.  And so should 
be removed. I suspect this is the case for a lot of fbdev drivers. Hence 
we should make a push to get drivers removed.

Best regards
Thomas

>
> Helge

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)