On Fri, 2012-08-31 at 11:53 +0530, Archit Taneja wrote: > The only little problem was that during bootup, when hwmods are setup, > only the 'parent' hwmod was able to get reset properly, all the other > 'child' hwmods don't have modulemode bits tied to them, and hence > weren't able to reset. So we got some error prints. > > Once DSS driver kicks in, the driver ensures the parent is enabled for > any child to be enabled, so we don't face the issue again. > > So, if DSS driver is not built in, and if the bootloader left DSS in a > bad state, the DSS clocks might remain messed up all the time since > hwmod fwk wasn't able to reset them. > > I think this is why we didn't proceed with remove "dss_fck" as a slave > clock. If this issue is minor, we could go ahead and remove it. I wonder if we could handle this with a custom reset function. We already have a reset func for dss core. If I remember right, the main point for that is the fact that omap4 doesn't have a softreset for dss core, so we manually write the default values to registers. For omap2/3 this would be simple: skip the resets for all other dss submodules, and dss core's reset would enable all the clocks and set the softreset bit. This would reset all the submodules also. Omap4 is more tricky. I guess we'd need to enable all the clocks, clear manually dss core's registers, and then set softreset bits in all the submodules. So in this case dss core would need to have information about the other submodules. Tomi
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