On 01/12/2020 02:17, Laurent Pinchart wrote: > Hi Tomi, > > Thank you for the patch. > > On Tue, Nov 24, 2020 at 02:45:22PM +0200, Tomi Valkeinen wrote: >> The "channel" usage in omap dsi driver is super confusing. We have three >> different "channels": >> >> 1) DSI virtual channel ID. This is a number from 0 to 3, included in the >> packet payload. >> >> 2) VC. This is a register block in the DSI IP. There are four of those >> blocks. A VC is a DSI "pipeline", with defined fifo settings, data >> source (cpu or dispc), and some other settings. It has no relation to >> the 1). > > Lovely that it's called VC :-) Yes. There are 4 VC blocks. My guess is that initially the HW designers meant that one HW VC block is used for one DSI channel (DSI supports 4 channels). But at least I cannot see how the HW could be used that way. >> 3) dispc channel. It's the "pipeline" number dispc uses to send pixel >> data. >> >> To clean this up use the following names for each of the above: 1) >> "channel" 2) "vc" 3) "dispc_channel" > > 1) and 2) will still be prone to confusion :-S Would it help to name 2) > hw_vc or something similar ? The omap dsi driver uses "vc" and "channel" consistently after this patch, and afaics in the DRM framework it's always "channel". So I kind of agree with you but I hope this is enough. Otherwise I'll spend lots of hours solving the conflicts after rename... Well, a new rename patch could be done later on top if needed. >> This patch is mostly about renaming things, but as in some places 1) and >> 2) have gotten mixed up, additional changes were needed to untangle >> them. This is mostly just adding a new parameter to some functions so >> that we pass both the vc and the channel. > > It would ease review if this could be split in two patches. Ok. I'll see if I can split this up without a huge amount of work. They are a bit tangled up... But I agree, this is a bit too big patch. Tomi -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
