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FREEMAIL_ENVRCPT(0.00)[gmail.com,gmx.de,outlook.com]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:106:10:150:64:167:received,2a07:de40:b281:104:10:150:64:97:from]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; TAGGED_RCPT(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; DKIM_TRACE(0.00)[suse.de:+]; RCVD_VIA_SMTP_AUTH(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo,suse.de:dkim,suse.de:mid,suse.de:email] X-Spam-Score: -3.01 Hi Am 12.09.25 um 05:24 schrieb Michael Kelley: > From: Prasanna Kumar T S M Sent: Thursday, September 11, 2025 9:28 AM >> Hi Michael, >> >> On 10-09-2025 20:55, Michael Kelley wrote: >>> From: Thomas Zimmermann Sent: Wednesday, September >> 10, 2025 2:36 AM >>>> Hi >>>> >>>> Am 09.09.25 um 18:58 schrieb Prasanna Kumar T S M: >>>>> The Hyper-V DRM driver is available since kernel version 5.14 and >>>>> provides full KMS support along with fbdev emulation via the DRM fbdev >>>>> helpers. This makes the hyperv_fb driver redundant, remove it. >>>> I'm all for removing obsolete drivers. But hyperv_drm likely first needs >>>> to merge the patch at >>>> https://lore.kernel.org/dri-devel/20250904145806.430568-5-tzimmermann@suse.de/ >>>> It's been tested and works well. If maintainers from Microsoft have a >>>> look at the patch first, we could possibly land it fairly soon. >>> Thomas -- >>> >>> My testing of your v3 patch series for vblank timers ended up getting a >>> WARN_ON after about 3 days of usage. See [1]. So I don't think it's 100% >>> ready yet. >>> >>> But I agree we need your synthetic vblank timer support to address the >>> Hyper-V DRM driver performance issue, before removing the Hyper-V >>> fbdev driver. (See [2] for a description of the performance issue.) >>> >>> Second, isn't it customary to mark a driver as deprecated for a period >>> of time, before removing it entirely? I don't see any documentation >>> on the deprecation process, but I've seen it done in other cases. If you >>> grep through all the kernel Kconfig files, you'll see entries tagged with >>> DEPRECATED. Also the driver should be updated to output a deprecated >>> message when it loads. >> Is deprecating the driver a mandatory step? >> > I'm not aware of a mandatory requirement, at least not in the sense > of it being documented in Documentation/process like other aspects > of the Linux kernel development process. So I would say it's up to > the Maintainers for Hyper-V and FBDEV as to whether the Hyper-V > FB driver should go through a deprecation phase before being > removed. > > Of course, the purpose of the deprecation phase is to be "nice" > to users of the driver by giving them some warning that it is going > away. That gives them an opportunity to raise objections, and/or > to do any necessary migration to the replacement driver. I suspect > there aren't many (or any?) users of Hyper-V FB that can't just move > to the Hyper-V DRM driver, but who knows. We might be surprised. Let's mark the driver as unmaintained now. There should be a kernel LTS release around December [1], after which hyperv-fb could be removed. Anyone with hard dependencies on hyperv-fb can remain in the LTS for a few more years. Best regards Thomas [1] https://www.kernel.org/category/releases.html > > Michael -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)