Messages in this thread |  | | Subject | Re: [PATCH 2/9] macintosh/via-macii: Poll the device most likely to respond | From | Guenter Roeck <> | Date | Sun, 9 Aug 2020 18:16:59 -0700 |
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Hi,
On 8/9/20 3:58 PM, Finn Thain wrote: > On Sun, 9 Aug 2020, Guenter Roeck wrote: > >> Hi, >> >> On Sun, Jun 28, 2020 at 02:23:12PM +1000, Finn Thain wrote: >>> Poll the most recently polled device by default, rather than the lowest >>> device address that happens to be enabled in autopoll_devs. This improves >>> input latency. Re-use macii_queue_poll() rather than duplicate that logic. >>> This eliminates a static struct and function. >>> >>> Fixes: d95fd5fce88f0 ("m68k: Mac II ADB fixes") # v5.0+ >>> Tested-by: Stan Johnson <userm57@yahoo.com> >>> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> >> >> With this patch applied, the qemu "q800" emulation no longer works and >> is stuck in early boot. Any idea why that might be the case, and/or how >> to debug it ? >> > > The problem you're seeing was mentioned in the cover letter, > https://lore.kernel.org/linux-m68k/cover.1593318192.git.fthain@telegraphics.com.au/ > > Since this series was merged, Linus' tree is no longer compatible with > long-standing QEMU bugs. > > The best way to fix this is to upgrade QEMU (latest is 5.1.0-rc3). Or use > the serial console instead of the framebuffer console. >
I have no problem with that. Actually, I had checked the qemu commit log, but somehow I had missed missed the commits there.
> I regret the inconvenience but the alternative was worse: adding code to > Linux to get compatibility with QEMU bugs (which were added to QEMU due to > Linux bugs). > > My main concern is correct operation on actual hardware, as always. But > some QEMU developers are working on support for operating systems besides > Linux. > > Therefore, I believe that both QEMU and Linux should aim for compatibility > with actual hardware and not bug compatibility with each other. > I absolutely agree.
I repeated the test on the mainline kernel with qemu v5.1-rc3, and it works. I also made sure that older versions of Linux still work with the qemu v5.1.0-rc3. So everything is good, and sorry for the noise.
Thanks, Guenter
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