On Thu, May 17, 2012 at 4:28 AM, Kevin Hilman <khilman@xxxxxx> wrote: > Tero Kristo <t-kristo@xxxxxx> writes: > >> From: Santosh Shilimkar <santosh.shilimkar@xxxxxx> >> >> The SAR RAM is maintained during Device OFF mode. > > so why is this patch bothering to save and restore it? > SAR RAM is maintained(not powered down) but somebody needs to feel the contents which will be preserved :-) > -ECONFUSED > >> The register layout >> is fixed in SAR ROM. SAR is split into 4 banks with different >> privilege accesses based on device type >> >> --------------------------------------------------------------- >> Access mode Bank Address Range >> --------------------------------------------------------------- >> HS/GP : Public 1 0x4A32_6000 - 0x4A32_6FFF (4kB) >> HS/GP : Public 2 0x4A32_7000 - 0x4A32_73FF (1kB) >> >> HS/EMU : Secured >> GP : Public 3 0x4A32_8000 - 0x4A32_87FF (2kB) >> >> HS/GP :Secure >> write once. 4 0x4A32_9000 - 0x4A32_93FF (1kB) >> --------------------------------------------------------------- >> >> The save process is done entirely by software and restore is done by >> hardware using the auto-restore feature. The restore feature is enabled >> by default and cannot be disabled. The software must save the data >> to be restored in a dedicated location in SAR RAM. > > Some general comments: > > - can the cluster PM notifier be used for the save path? > Nope. This is for device OFF only case. CPU Cluster state as such has no dependency. > - This patch adds lots of data that is immediately removed by the next > patch. Probably the two just need to be combined. > iormap() hunk from this patch can be completely dropped since it is getting fixed in next patch. Other infrastructure is maintained. > - BUG_ON() should not be used unless there is absolutely no recovery > path, since it casues a full kernel panic. Instead, some error > recovery should be added. > WARN_ON should suffice. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
