Hi Bjorn, On Sonntag, 6. Februar 2022 21:17:22 CET Luca Weiss wrote: > Hi Bjorn, > > On Montag, 31. Jänner 2022 23:32:42 CET Bjorn Andersson wrote: > > On Sun 16 Jan 10:30 CST 2022, Stephan Gerhold wrote: > > > On Sun, Jan 16, 2022 at 05:08:29PM +0100, Luca Weiss wrote: > > > > On Mittwoch, 12. Jänner 2022 22:39:53 CET Stephan Gerhold wrote: > > > > > On Wed, Jan 12, 2022 at 08:40:58PM +0100, Luca Weiss wrote: > > > > > > From: Vladimir Lypak <vladimir.lypak@xxxxxxxxx> > > > > > > > > > > > > RPM Firmware on variety of newer SoCs such as MSM8917 (also likely > > > > > > MSM8937, MSM8940, MSM8952), MSM8953 and on some MSM8916 devices) > > > > > > doesn't > > > > > > initiate opening of the SMD channel if it was previously opened by > > > > > > bootloader. This doesn't allow probing of smd-rpm driver on such > > > > > > devices > > > > > > because there is a check that requires RPM this behaviour. > > > > > > > > > > > > Signed-off-by: Vladimir Lypak <vladimir.lypak@xxxxxxxxx> > > > > > > Signed-off-by: Luca Weiss <luca@xxxxxxxxx> > > > > > > Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx> > > > > > > > > > > This is effectively a "Revert "Revert "rpmsg: smd: Create device for > > > > > all > > > > > channels""": > > > > > > > > > > https://lore.kernel.org/linux-arm-msm/20171212235857.10432-3-bjorn.a > > > > > nd > > > > > ersson @linaro.org/ > > > > > https://lore.kernel.org/linux-arm-msm/20180315181244.8859-1-bjorn.an > > > > > de > > > > > rsson > > > > > @linaro.org/ > > > > > > > > > > Won't this cause the same regression reported by Srinivas again? > > > > > > > > Do you have any suggestion on another way to solve this? Without this > > > > commit the regulators just won't probe at all, I haven't looked very > > > > deep into it though given this patch solves it. > > > > > > > > I guess worst case it'll become a devicetree property to enable this > > > > quirk? > > > > > > My spontaneous suggestion would be to skip the check only for the > > > "rpm_requests" channel, e.g. something like > > > > > > if (remote_state != SMD_CHANNEL_OPENING && > > > > > > remote_state != SMD_CHANNEL_OPENED && > > > strcmp(channel->name, "rpm_requests") > > > > > > continue; > > > > > > This will avoid changing the behavior for anything but the RPM channel. > > > I don't think anything else is affected by the same problem (since the > > > bootloader or earlier firmware should not make use of any other > > > channel). > > > Also, we definitely *always* want to open the channel to the RPM because > > > otherwise almost everything breaks. > > > > Last time this came up I asked if someone could test if the RPM is stuck > > in the state machine trying to close the channel and as such we could > > kick it by making sure that we "ack" the closing of the channel and > > hence it would come back up again. > > > > But I don't remember seeing any outcome of this. > > Do you have a link to this or should I go digging in the archives? Replying to myself, I went searching but couldn't find anything. If you have some PoC code I'd be happy to try but as I'm not familiar with rpm/smd at all I'd have to read myself into it first. If Stephans suggestion with the strcmp(channel->name, "rpm_requests") is ok then I'd test this and use that in v2. I'd personally rather not spend too much time on this issue right now as it's blocking msm8953 completely (no regulators = no nothing), Regards Luca > > Regards > Luca > > > > Many solutions are possible though so at the end it is mostly up to > > > Bjorn to decide I think. :) > > > > I would prefer to get an answer to above question, but if that doesn't > > work (or look like crap) I'm willing to take your suggestion of skipping > > the continue for the rpm_requests channel. Obviously with a comment > > above describing why we're carrying that special case. > > > > Regards, > > Bjorn
