Peter Maydell <[email protected]> writes:
> The tsc210x doesn't support anything other than 16-bit reads on the > SPI bus, but the guest can program the SPI controller to attempt > them anyway. If this happens, don't abort QEMU, just log this as > a guest error. > > This fixes our machine_arm_n8x0.py:N8x0Machine.test_n800 > acceptance test, which hits this assertion. > > The reason we hit the assertion is because the guest kernel thinks > there is a TSC2005 on this SPI bus address, not a TSC210x. (The n810 > *does* have a TSC2005 at this address.) The TSC2005 supports the > 24-bit accesses which the guest driver makes, and the TSC210x does > not (that is, our TSC210x emulation is not missing support for a word > width the hardware can handle). It's not clear whether the problem > here is that the guest kernel incorrectly thinks the n800 has the > same device at this SPI bus address as the n810, or that QEMU's n810 > board model doesn't get the SPI devices right. At this late date > there no longer appears to be any reliable information on the web > about the hardware behaviour, but I am inclined to think this is a > guest kernel bug. In any case, we prefer not to abort QEMU for > guest-triggerable conditions, so logging the error is the right thing > to do. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/736 > Signed-off-by: Peter Maydell <[email protected]> Reviewed-by: Alex Bennée <[email protected]> -- Alex Bennée
