On Tue, Oct 22, 2013 at 9:15 PM, Inki Dae <inki.dae at samsung.com> wrote:
> 2013/10/23 St?phane Marchesin <stephane.marchesin at gmail.com>: > > > > > > > > On Tue, Oct 22, 2013 at 8:38 PM, Inki Dae <inki.dae at samsung.com> wrote: > >> > >> 2013/10/23 St?phane Marchesin <stephane.marchesin at gmail.com>: > >> > > >> > > >> > > >> > On Tue, Oct 22, 2013 at 7:28 PM, Inki Dae <inki.dae at samsung.com> > wrote: > >> >> > >> >> 2013/10/22 Sean Paul <seanpaul at chromium.org>: > >> >> > On Tue, Oct 22, 2013 at 1:30 AM, Inki Dae <inki.dae at samsung.com> > >> >> > wrote: > >> >> >> > >> >> >> > >> >> >>> -----Original Message----- > >> >> >>> From: Sean Paul [mailto:seanpaul at chromium.org] > >> >> >>> Sent: Tuesday, October 22, 2013 6:18 AM > >> >> >>> To: Inki Dae > >> >> >>> Cc: dri-devel; Dave Airlie; Tomasz Figa; St?phane Marchesin > >> >> >>> Subject: Re: [PATCH v2 12/26] drm/exynos: Split > >> >> >>> manager/display/subdrv > >> >> >>> > >> >> >>> On Mon, Oct 21, 2013 at 10:46 AM, Sean Paul < > seanpaul at chromium.org> > >> >> >>> wrote: > >> >> >>> > On Thu, Oct 17, 2013 at 10:31 PM, Inki Dae < > inki.dae at samsung.com> > >> >> >>> > wrote: > >> >> >>> >> > >> >> >>> >> > >> >> >>> >>> -----Original Message----- > >> >> >>> >>> From: Sean Paul [mailto:seanpaul at chromium.org] > >> >> >>> >>> Sent: Thursday, October 17, 2013 11:37 PM > >> >> >>> >>> To: Inki Dae > >> >> >>> >>> Cc: dri-devel; Dave Airlie; Tomasz Figa; St?phane Marchesin > >> >> >>> >>> Subject: Re: [PATCH v2 12/26] drm/exynos: Split > >> >> >>> >>> manager/display/subdrv > >> >> >>> >>> > >> >> >>> >>> On Thu, Oct 17, 2013 at 4:21 AM, Inki Dae > >> >> >>> >>> <inki.dae at samsung.com> > >> >> >> wrote: > >> >> >>> >>> > > >> >> >>> >>> > > >> >> >>> >>> >> -----Original Message----- > >> >> >>> >>> >> From: Sean Paul [mailto:seanpaul at chromium.org] > >> >> >>> >>> >> Sent: Thursday, October 17, 2013 4:27 AM > >> >> >>> >>> >> To: dri-devel at lists.freedesktop.org; inki.dae at > >> >> >>> >>> >> samsung.com > >> >> >>> >>> >> Cc: airlied at linux.ie; tomasz.figa at gmail.com; > >> >> >>> >>> >> marcheu at chromium.org; > >> >> >>> Sean > >> >> >>> >>> >> Paul > >> >> >>> >>> >> Subject: [PATCH v2 12/26] drm/exynos: Split > >> >> >>> >>> >> manager/display/subdrv > >> >> >>> >>> >> > >> >> >>> >>> >> This patch splits display and manager from subdrv. The > >> >> >>> >>> >> result > >> >> >>> >>> >> is > >> >> >>> that > >> >> >>> >>> >> crtc functions can directly call into manager callbacks > and > >> >> >>> >>> >> encoder > >> >> >>> >>> >> functions can directly call into display callbacks. This > >> >> >>> >>> >> will > >> >> >>> >>> >> allow > >> >> >>> >>> >> us to remove the exynos_drm_hdmi shim and support > mixer/hdmi > >> >> >>> >>> >> & > >> >> >>> fimd/dp > >> >> >>> >>> >> with common code. > >> >> >>> >>> >> > >> >> >>> >>> >> Signed-off-by: Sean Paul <seanpaul at chromium.org> > >> >> >>> >>> >> --- > >> >> >>> >>> >> > >> >> >>> >>> >> Changes in v2: > >> >> >>> >>> >> - Pass display into display_ops instead of context > >> >> >>> >>> > > >> >> >>> >>> > Sorry but it seems like more reasonable to pass device > object > >> >> >>> >>> > into > >> >> >>> >>> > display_ops and manager_ops. > >> >> >>> >>> > > >> >> >>> >>> > >> >> >>> >>> > >> >> >>> >>> So you've changed your mind from when you said the following? > >> >> >>> >>> > >> >> >>> >>> >>> manager->ops->xxx(manager, ...); > >> >> >>> >>> >>> display->ops->xxx(display, ...); > >> >> >>> >>> >>> > >> >> >>> >>> >>> Agree. > >> >> >>> >>> > >> >> >>> >> > >> >> >>> >> > >> >> >>> >> True. Before that, My comment was to pass device object into > >> >> >>> display_ops and > >> >> >>> >> manager_ops, and then you said the good solution is to pass > >> >> >>> >> manager > >> >> >>> >> and > >> >> >>> >> display to each driver. At that time, I thought no matter how > >> >> >>> >> the > >> >> >>> callback > >> >> >>> >> is called if the framework doesn't call callbacks of each > driver > >> >> >>> >> with > >> >> >>> ctx. > >> >> >>> >> So I agreed. > >> >> >>> >> > >> >> >>> >> > >> >> >>> >>> It would have been nice if you had changed your mind > *before* I > >> >> >>> >>> reworked everything. At any rate, I think it's still the > right > >> >> >>> >>> thing > >> >> >>> >>> to do. > >> >> >>> >> > >> >> >>> >> Really sorry about that. And I will add new patch for it so > you > >> >> >>> >> don't > >> >> >>> need > >> >> >>> >> to concern about that. > >> >> >>> >> > >> >> >>> >>> > >> >> >>> >>> > >> >> >>> >>> > I'm not sure but display_ops could be implemented in other > >> >> >>> >>> > framework > >> >> >>> >>> based > >> >> >>> >>> > driver such as CDF based lcd panel driver. So if you pass > >> >> >>> >>> > display - > >> >> >>> it's > >> >> >>> >>> > specific to exynos drm framework - into display_ops, the > >> >> >>> >>> > other > >> >> >>> framework > >> >> >>> >>> > based driver should include specific exynos drm header. > >> >> >>> >>> > > >> >> >>> >>> > >> >> >>> >>> AFAIK, CDF will not land in its current separate-from-drm > form, > >> >> >>> >>> we > >> >> >>> >>> don't need to worry about this. Furthermore, these ops should > >> >> >>> >>> just > >> >> >>> >>> go > >> >> >>> >>> away and become drm_crtc/drm_encoder/drm_connector funcs > >> >> >>> >>> anyways. > >> >> >>> >>> > >> >> >>> >> > >> >> >>> >> Can you assure the display_ops never implemented in other > >> >> >>> >> framework > >> >> >>> based > >> >> >>> >> driver, not CDF? At any rate, I think all possibilities should > >> >> >>> >> be > >> >> >>> opened. > >> >> >>> >> > >> >> >>> > > >> >> >>> > I don't think we should let an RFC framework make the code more > >> >> >>> > complicated for unclear benefit. By removing manager/display > >> >> >>> > entirely, > >> >> >>> > we can get rid of a *lot* of other code that is basically just > >> >> >>> > plumbing drm hooks (exynos_drm_connector is a good example). > >> >> >>> > > >> >> >>> > >> >> >>> I hacked this up today to prove it out. Check out the top 5 > commits > >> >> >>> in > >> >> >>> > >> >> >>> > >> >> >>> > https://github.com/crseanpaul/exynos-drm-next/commits/linux-next-exynos- > >> >> >>> staging. > >> >> >>> It removes exynos_drm_connector in favor of just implementing > >> >> >>> drm_connector directly. This same treatment should be done for > >> >> >>> exynos_drm_encoder and exynos_drm_crtc, but I didn't get around > to > >> >> >>> doing this. > >> >> >>> > >> >> >>> As you can see, it cuts out a lot of code and removes an entire > >> >> >>> abstraction layer. Much nicer :) > >> >> >>> > >> >> >> > >> >> >> It seems that you implements connector in each device driver. > Can't > >> >> >> they be > >> >> >> combined as common spot, exynos_connector, again to avoid codes > from > >> >> >> duplicated? :) > >> >> > > >> >> > There's nothing of substance being duplicated. > >> >> > >> >> Not true. xxx_create_connector is duplicated. > >> >> > >> >> > In fact, by getting rid > >> >> > of the exynos_drm_connector layer, we deleted 150 lines. If you > >> >> > really > >> >> > take a look at exynos_drm_connector, it's not doing anything > useful. > >> >> > >> >> No, That is for each driver has no any dependency of drm framework. > >> >> > >> >> > All it does is translate the drm callbacks into display callbacks, > so > >> >> > I think it's much better to just implement the drm callbacks > >> >> > directly. > >> >> > > >> >> > >> >> No, It has strongly dependency of drm framework. Assume that we > >> >> implemented the drm callbacks directly, and then some features are > >> >> added to drm framework, drm_connector side. At this time, we will > have > >> >> to take care of each device driver according to the change. That is > >> >> really not good. Why device drivers should have dependency of drm > >> >> framework? Just to reduce line counts? > >> > > >> > > >> > > >> > You seem to miss the point here and elsewhere in the discussion. > >> > drm/exynos is a drm driver, and as such it should use the drm > >> > framework, > >> > >> Hm.. you seem to miss something. Exynos drm based drivers are based on > >> exynos drm framework, not drm framework directly. So I mean that > >> Exynos drm framework based drivers should include only Exynos drm > >> headers, _not drm header_ directly. > > > > > > Well, I think everyone sees that exynos is different. But my point still > > remains: why is the exynos driver in drm/ if it wants to use a different > > framework? Right now it is blocking work on a proper drm driver... > > > > Noooooo. It's not to use a different framework. It's to use a wrapper > instead. > Ok, if you want to call it a wrapper, then what is the point of doing this wrapping given that it prevents a proper drm-style implementation? > > > >> > >> > >> > especially if this reduces the line count and the code > >> > complexity (as is the case for this patch series). If you don't want > >> > to maintain a drm driver, it simply should be moved away from drm/, > >> > and it should be replaced by a real drm driver in my opinion. > >> > >> So those drivers should be in drm/exynos. Isn't that you really mean > >> those drivers should be driver/gpu/drm? > > > > > > I don't understand this sentence, sorry. > > Sorry, again, you mean Exynos drm based drivers should be in > drivers/gpu/drm, not drivers/gpu/drm/exynos? > > Is the exynos drm useful in its current shape at all? My recommendation would be to fork off a real drm driver in gpu/drm/exynos with the current code as a base. St?phane > Thanks, > Inki Dae > > > > > St?phane > > > > > >> > >> If so, That would really be > >> horrible. :( > >> > > > > > >> > >> Please, know that only Exynos drm framework, _not device drivers_, has > >> all dependencies of drm framework, and also I know that other ARM > >> based drm drivers are using same way. > >> > >> Thanks, > >> Inki Dae > >> > >> > > >> > St?phane > >> > > >> >> > >> >> > >> >> > There are a bunch of real bugs that we've found as a result of > having > >> >> > these abstraction layers. Take, for example, dpms. Before this > >> >> > patchset, dpms for fimd was being tracked separately in fimd > driver, > >> >> > exynos_drm_encoder, exynos_drm_crtc, and exynos_drm_connector. > >> >> > Furthermore, during suspend, only fimd driver's dpms state was > >> >> > updated, so the others were incorrect. There was also this weird > >> >> > gymnastics that had to happen when dpms was changed in the encoder > >> >> > since it had to walk up to the connector level to change its dpms > >> >> > state. If fimd just directly implemented > >> >> > drm_crtc/drm_encoder/drm_connector (before dp was moved in), this > >> >> > problem wouldn't exist. The same goes for HDMI/mixer. > >> >> > > >> >> > >> >> That is a issue we should take care of by using the independent > layer. > >> >> Then, aren't you take care of that well with the re-factoring patch > >> >> set? :) It seems that you are outside real point. > >> >> > >> >> > Take a look at exynos_drm_encoder.c in my tree > >> >> > > >> >> > > >> >> > ( > https://github.com/crseanpaul/exynos-drm-next/blob/linux-next-exynos-staging/drivers/gpu/drm/exynos/exynos_drm_encoder.c > ), > >> >> > what does it do that's useful to abstract? All that it does is just > >> >> > call display ops, it's completely useless. The same is true for > >> >> > exynos_drm_connector, it's just dead weight. There is some useful > >> >> > stuff in exynos_drm_crtc for page flipping, that would be better > >> >> > served as a helper library, though. > >> >> > > >> >> >> The abstraction layer you mentioned also means a common spot. > >> >> >> Another one, you patch also makes each sub driver have strongly > >> >> >> dependency > >> >> >> of drm framework. So how we can support existing backlight and lcd > >> >> >> class > >> >> >> based lcd panel drivers if the connector is implemented in each > >> >> >> device > >> >> >> driver later? the drm header files should be included in > >> >> >> drivers/video/backlight/xxx_lcd.c? > >> >> >> > >> >> > > >> >> > drm_bridge or drm_panel seem like good candidates for this. > >> >> > > >> >> > >> >> Yes, exynos_drm_display could be replaced with drm_panel later if the > >> >> drm_panel can be merged to mainline. > >> >> > >> >> > > >> >> >> And, I will introduce a new framework to support existing lcd > panel > >> >> >> drivers > >> >> >> and display bus drivers soon; as of now for Exynos drm, and the > >> >> >> framework is > >> >> >> being tested internally. With this framework, encoder and > connector > >> >> >> will be > >> >> >> created when lcd panel or display bus driver such as eDP is > probed: > >> >> >> it > >> >> >> doesn?t really need to create encoder and connector in advance if > >> >> >> lcd > >> >> >> panel > >> >> >> or display bus driver isn't probed yet. Regardless of crtc, and > >> >> >> encoder > >> >> >> and > >> >> >> connector creation order, when last one is created, crtc and > >> >> >> connector > >> >> >> will > >> >> >> be connected each other. And exynos_drm_display could be > implemented > >> >> >> in > >> >> >> other frameworks if we have common structure for display device > >> >> >> driver. > >> >> >> And > >> >> >> also the framework will support lvds driver according to Linux > >> >> >> device > >> >> >> driver > >> >> >> model. > >> >> >> > >> >> > > >> >> > I don't really follow what you're trying to do here, but I think we > >> >> > should be moving in the direction of fewer abstractions in the > exynos > >> >> > driver, not more :) > >> >> > > >> >> > >> >> Not abstraction layer, just a bridge for connecting crtc and its > >> >> corresponding encoder/connector, and lvds regardless of creation > >> >> order, and for connecting drm connector and other framework based > >> >> display ops such as drm_panel later. > >> >> > >> >> > Sean > >> >> > > >> >> > > >> >> > > >> >> >> Thanks, > >> >> >> Inki Dae > >> >> >> > >> >> >>> Sean > >> >> >>> > >> >> >>> >>> > >> >> >>> >>> > And another one, the patch 6 passes manager object to > >> >> >>> >>> > manager_ops, > >> >> >>> and > >> >> >>> >>> for > >> >> >>> >>> > this, you made the manager object to be set to driver data; > >> >> >>> >>> > platform_set_drvdata(pdev, &manager). That isn't > reasonable. > >> >> >>> Generally, > >> >> >>> >>> > driver_data would point to device driver's context object. > >> >> >>> >>> > > >> >> >>> >>> > >> >> >>> >>> I'm not sure why this isn't reasonable, but it's a moot > point. > >> >> >>> >>> The > >> >> >>> >>> driver data is only used up until we get rid of the pm ops, > it > >> >> >>> >>> needn't > >> >> >>> >>> be set at all once things go through dpms. > >> >> >>> >>> > >> >> >>> >> > >> >> >>> >> Generally, device drivers can call its own internal functions, > >> >> >>> >> and > >> >> >>> >> they > >> >> >>> will > >> >> >>> >> call that functions with ctx. However, if you set manager to > >> >> >>> driver_data > >> >> >>> >> then that functions should be called with manager object and > >> >> >>> >> also > >> >> >>> internally > >> >> >>> >> that functions should get ctx from the manager object. What is > >> >> >>> >> the > >> >> >>> purpose > >> >> >>> >> of manager? Do you think it's reasonable? > >> >> >>> >> > >> >> >>> > > >> >> >>> > So, to avoid setting the manager as the drvdata, we could > >> >> >>> > implement > >> >> >>> > something like fimd_dpms_ctx(ctx, mode) that takes ctx and the > >> >> >>> > manager > >> >> >>> > callback calls it fimd_dpms(mgr, mode) { ctx = mgr->ctx; > >> >> >>> > fimd_dpms_ctx(ctx, mode); }. Alternatively, you can save a > >> >> >>> > pointer > >> >> >>> > to > >> >> >>> > mgr in ctx, but that creates a circular link between the two. > >> >> >>> > IMO, > >> >> >>> > both of those solutions suck :) > >> >> >>> > > >> >> >>> > I'd much rather just set drvdata to the manager and call the > hook > >> >> >>> > directly. Like I said earlier, this is just a temporary step > >> >> >>> > since > >> >> >>> > we > >> >> >>> > remove these pm ops later in the patch series. > >> >> >>> > > >> >> >>> > Sean > >> >> >>> > > >> >> >>> > > >> >> >>> >> Anyway, I'd like to say really sorry about inconvenient again. > >> >> >>> >> So I > >> >> >>> will fix > >> >> >>> >> it. > >> >> >>> >> > >> >> >>> >> Thanks, > >> >> >>> >> Inki Dae > >> >> >>> >> > >> >> >>> >>> Sean > >> >> >>> >>> > >> >> >>> >>> > >> >> >>> >>> > Thanks, > >> >> >>> >>> > Inki Dae > >> >> >>> >>> > > >> >> >>> >> > >> >> >> > >> >> > _______________________________________________ > >> >> > dri-devel mailing list > >> >> > dri-devel at lists.freedesktop.org > >> >> > http://lists.freedesktop.org/mailman/listinfo/dri-devel > >> >> _______________________________________________ > >> >> dri-devel mailing list > >> >> dri-devel at lists.freedesktop.org > >> >> http://lists.freedesktop.org/mailman/listinfo/dri-devel > >> > > >> > > >> > > >> > _______________________________________________ > >> > dri-devel mailing list > >> > dri-devel at lists.freedesktop.org > >> > http://lists.freedesktop.org/mailman/listinfo/dri-devel > >> > > > > > > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel at lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/dri-devel > > > -------------- next part -------------- An HTML attachment was scrubbed... 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