Messages in this thread | | | Subject | Re: [PATCH] Revert "clk: imx: fix composite peripheral flags" | From | Martin Kepplinger <> | Date | Thu, 7 Jan 2021 16:11:58 +0100 |
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On 04.01.21 13:05, Abel Vesa wrote: > On 20-12-31 17:33:40, Fabio Estevam wrote: >> Hi Martin, >> >> On Thu, Dec 31, 2020 at 11:22 AM Martin Kepplinger >> <martin.kepplinger@puri.sm> wrote: >>> >>> This reverts commit 936c383673b9e3007432f17140ac62de53d87db9. >>> >>> It breaks clock reparenting via devfreq on the imx8mq used in the >>> Librem 5 phone. When switching dram frequency (which worked before) >>> the system now hangs after this where the dram_apb clock cannot be >>> set: >>> >>> [ 129.391755] imx8m-ddrc-devfreq 3d400000.memory-controller: failed to >>> set dram_apb parent: -16 >>> [ 129.391959] imx8m-ddrc-devfreq 3d400000.memory-controller: ddrc >>> failed freq switch to 25000000 from 800000000: error -16. now at 25000000 >>> [ 129.406133] imx8m-ddrc-devfreq 3d400000.memory-controller: failed to >>> update frequency from PM QoS (-16) >> >> I am wondering whether IMX8MQ_CLK_DRAM_ALT should also be marked as >> CLK_IS_CRITICAL. >> > > Hmm, the way the DRAM clocks are right registered right now is a real mess. > The DRAM clocks on i.MX8M are changed in TF-A, but the kernel still needs to > register them to keep track of the clock tree. > > Martin, I already have a patchset waiting to be shipped which doesn't > only fix the 8MQ, but all the 8M platforms. Unfortunately, I haven't had the time > to work on that in the last couple of weeks but I intend to switch back to it soon. > > Fabio, marking the DRAM clocks as critical will not allow the set_parent to be done, > as CLK_IS_CRITICAL flag and set_parent do not go together. As of now the devfreq > tries to reparent to be consistent with TF-A configuration. > > My approach here was to make the DRAM clocks read-only. This means adding some > stuff in the clock core subsystem too.
Hi Abel, thanks a lot for the update. I'm looking forward to seeing your patchset.
martin
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