On Fri, May 18, 2018 at 5:15 PM, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, May 18, 2018 at 06:08:24PM +0300, Heikki Krogerus wrote: >> >> Rafael, the problem here with these Dell laptops is that a memory page >> that is used as a mailbox for special communication between EC FW and >> OS (called UCSI mailbox) should be in uncached memory, but the memory >> is marked as cached. Well, why don't we map it as uncached, then? >> I'm actually not even sure if the cache mode is something that is set >> based on information from ACPI tables, or is it something that the >> BIOS handles separately? We map the ACPI tables as cached as a rule, so that may be the reason. >> If it's information coming from ACPI tables, can we help pin point the >> place the BIOS guys at Dell should fix? I'm not sure where this particular piece comes from. > Given that Windows works with this same set of ACPI tables, perhaps the > requirement isn't that this memory location be uncached? > > We shouldn't have to fix up ACPI tables just for Linux, we've been down > that path before :( Yes, pretty much. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html