Messages in this thread | | | Date | Tue, 08 Jan 2019 16:20:41 +0530 | From | Sibi Sankar <> | Subject | Re: [PATCH v2 1/2] dt-bindings: remoteproc: qcom: Add firmware bindings for Q6V5 |
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Hi Brian/Bjorn, Thanks for the review!
On 2019-01-05 07:24, Brian Norris wrote: > Hi again, > > On Thu, Jan 03, 2019 at 04:11:58PM -0800, Brian Norris wrote: >> On Thu, Jan 03, 2019 at 04:01:45PM -0800, Bjorn Andersson wrote: >> > I share your concern about this, but I came to suggest this as the >> > driver cares about platforms but the firmware is (often?) >> > device/product-specific. >> > >> > E.g. we will serve the MTP and Pixel 3 with the qcom,sdm845-adsp-pas >> > compatible, but they are unlikely to run the same adsp firmware. This >> > allows the individual dtb to specify which firmware the driver should >> > use. >> >> I understand this, but that still doesn't mean we should be suggesting >> each DTB to clutter the top-level firmware search path, especially >> since >> lazy people will probably just use "modem.mdt" and similar. That means >> you no longer can ship the same rootfs that supports both QCOM and >> <other> modems, if <other> modem also uses the same lazy format. >> >> It seems like a much better practice to at least enforce a particular >> prefix to things. e.g., the driver could assume: >> >> qcom/sdm845-adsp-pas/ (or if you must, just qcom/) >> >> and your DTB only gets to add .../<your-string-here> to that path. >> >> In case it isn't clear: I think it's also severely misguided that the >> existing driver gets away with lines like >> >> request_firmware(&fw, "modem.mdt", ...); >> >> today ;) > > To add to my thoughts, since I think maybe Sibi was a little unclear of > my thoughts: > > One of my primary concerns with the existing approach is that it's > basically a complete free-for-all. We should have some minimal > standards > (enforced in code) such that our DTB can never point us at something > like /lib/firmware/<other-vendor>/foo.bin (or /lib/firmware/modem.mdt; > or lots of other bad examples). This could probably be done simply by > always prefixing 'qcom/' (I don't remember -- does request_firmware() > follow '..'? e.g., 'firmware-name = "../bar/foo.bin"'.) > > As a bonus: it would be very nice if we can provide a little more > structure by default, and avoid arbitrary hierarchy in the DTS. That's > where I brought up ath10k's "variant" as an example; if we can use > 'compatible' to capture most of this particular Hexagon core's > properties, then we only leave a single level of variability to the > DTS. > > But I might be off-base with the "bonus" paragraph. So I'd also be > somewhat happy with something much less ambitious, like just a built-in > prefix ('qcom/'). > > And you can also just ignore my thoughts entirely (and I'll be even > less > happy), since Rob did already provide his Reviewed-by ;) I mostly > wanted > to give food for thought, in the hopes that something in here would > help > improve this a bit.
Bjorn, let me know how you want it implemented. I am okay with either of the following: * (variant tag based solution) or * (simply going ahead with what we have now).
> > Regards, > Brian
-- -- Sibi Sankar -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
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