On 1/8/2025 4:13 PM, Hans Verkuil wrote: > On 1/8/25 11:21, Dikshita Agarwal wrote: >> >> >> On 1/8/2025 2:25 PM, Hans Verkuil wrote: >>> On 08/01/2025 09:51, Dikshita Agarwal wrote: >>>> >>>> >>>> On 1/8/2025 1:17 PM, Hans Verkuil wrote: >>>>> On 08/01/2025 08:43, Dikshita Agarwal wrote: >>>>>> >>>>>> >>>>>> On 1/7/2025 7:27 PM, Nicolas Dufresne wrote: >>>>>>> Le lundi 23 décembre 2024 à 16:21 +0530, Dikshita Agarwal a écrit : >>>>>>>> >>>>>>>> On 12/23/2024 4:00 PM, Mauro Carvalho Chehab wrote: >>>>>>>>> Em Thu, 12 Dec 2024 17:21:49 +0530 >>>>>>>>> Dikshita Agarwal <quic_dikshita@xxxxxxxxxxx> escreveu: >>>>>>>>> >>>>>>>>>> + .dma_mask = GENMASK(31, 29) - 1, >>>>>>>>> >>>>>>>>> Setting a mask to GENMASK() - 1 sounds weird. Is it really what you want? >>>>>>>>> I so, why? >>>>>>>>> >>>>>>>> Hi Mauro, >>>>>>>> >>>>>>>> the value of this dma mask should be 0xe0000000 -1. >>>>>>>> >>>>>>>> The background for the same is, 0xe0000000 onward memory space is allocated >>>>>>>> for IO register space so we are restricting the driver buffer allocations >>>>>>>> to 0xe0000000 - 1. >>>>>>>> >>>>>>>> Based on the comments received in the past, we are using GENMASK to >>>>>>>> generate 0xe0000000. >>>>>>>> >>>>>>>> Does this answer your query or I missed something? >>>>>>> >>>>>>> I'm not sure it will do what you want. (0xe0000000 -1) matches ~BIT(29). Perhaps >>>>>>> you wanted to use ~0xe0000000. >>>>>>> >>>>>> value of dma mask is coming as expected with GENMASK(31, 29) - 1 >>>>>> >>>>>> qcom-iris aa00000.video-codec: dma_mask DFFFFFFF (0xe0000000 -1) >>>>> >>>>> Isn't this just the equivalent of GENMASK(28, 0)? Can't you use that? >>> >>> Too early in the morning, this suggestion was clearly wrong. >>> >>>>> >>>>> It's much easier to understand than GENMASK()-1. >>>> >>>> Sure, I can use either ~GENMASK(29, 29) or ~BIT(29), >>> >>> ~BIT(29). >>> >>> It's really weird to just disable a single bit, so I think some comments >>> explaining why this mask is needed would be good (if there aren't comments >>> already). >>> >> I tested this some more, and seems ~BIT(29) doesn't work, as its still >> conflicting with the register space. > > Odd, perhaps a 64 vs 32 bit issue? > >> Correct value would be GENMASK(31,30) + GENMASK(28,0) to set the exact bits >> to get the desired value i.e 0xe0000000 -1 > > Honestly, in this case I would prefer to just go with the actual hex value > 0xdfffffff together with an explanatory comment. > We moved to GENMASK way to address comment on previous version, but sure can directly use 0xdfffffff with a comment. Thanks, Dikshita > Regards, > > Hans > >>> Regards, >>> >>> Hans >>> >>>> Please let me know which would be better? >>>> >>>> Thanks, >>>> Dikshita >>>> >>>>> >>>>> Regards, >>>>> >>>>> Hans >>>>> >>>>>> >>>>>> Thanks, >>>>>> Dikshita >>>>>>> Nicolas >>>>>>> >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Dikshita >>>>>>>>> Thanks, >>>>>>>>> Mauro >>>>>>> >>>>> >>>>> >>> >
