On Mon, Aug 21, 2023 at 12:35 PM Robert Marko <robimarko@xxxxxxxxx> wrote: > On Mon, 21 Aug 2023 at 21:31, Rob Herring <robh@xxxxxxxxxx> wrote: > > Why can't you just disable SDI unconditionally when going into debug > > mode? Is doing that when not enabled going to crash the system or > > something? I asked the same, to resounding silence: https://lore.kernel.org/all/20200721080054.2803881-1-computersforpeace@xxxxxxxxx/ https://lore.kernel.org/all/ZNlhSdh0qDMieTAS@localhost/ > Because if not disabled you will enter the Secure Debug mode even on a > regular reboot and then you have to pull the power in order to boot again. > Even according to QCA docs they intended for the Linux to disable SDI as > TZ/QSEE will always enable it as part of booting. NB: I've never read such docs. Presumably they're internal/private to Qualcomm and/or its direct partners? I'd love to see them. But, I think you (robinmarko) are not really answering the same question that Rob (robh) is asking. Rob is asking why you ever *don't* want to disable SDI. You're answering why we ever need to disable it at all. I don't think the latter question is controversial. FWIW, your description of those docs sounds like we should unconditionally *disable* SDI (like my first RFC above), which would answer Rob's question, and would agree with my RFC above :) And as a bonus, no Device Tree change would be required. Brian
