On Mon, 25 Aug 2025 at 00:00, Vadim Chichikalyuk <chichikal...@gmail.com> wrote: > > > > On 18 Aug 2025, at 18:26, Peter Maydell <peter.mayd...@linaro.org> wrote: > > > > So, what's the rationale here? QEMU's UART doesn't care about > > clocks at all. We provide a clock in the DTB because the kernel > > refuses to boot if you don't, but if the ACPI spec didn't even > > have a way to pass the clock frequency until rev 4 this obviously > > isn't a problem on that side. > > The rationale is the same – just as the (Linux?) kernel expects > a clock frequency if a UART is present in the DTB, guests using > ACPI may expect a valid value for the clock frequency in the > SPCR record when one is present.
But the ACPI spec prior to rev 4 doesn't even provide a way to specify the clock frequency, so why would a guest expect it, and how could it do so? thanks -- PMM
