Hi Doug, Hope you had a good holiday. On Mon, Jul 08, 2024 at 04:57:55PM -0700, Doug Anderson wrote: > On Thu, Jul 4, 2024 at 3:31 AM Greg Kroah-Hartman > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Thu, Jul 04, 2024 at 12:18:02PM +0200, Johan Hovold wrote: > > > Since 6.10-rc1, Qualcomm machines with a serial port can easily lock up > > > hard, for example, when stopping a getty on reboot. > > > > > > This was triggered by the kfifo conversion, which turned an existing bug > > > that caused the driver to print discarded characters after a buffer > > > flush into a hard lockup. > > > > > > This series fixes the regression and a related soft lockup issue that > > > can be triggered on software flow control and on suspend. > > > > > > Doug has posted an alternative series of fixes here that depends on > > > reworking the driver a fair bit here: > > > > > > https://lore.kernel.org/lkml/20240610222515.3023730-1-dianders@xxxxxxxxxxxx/ > > > > > > This rework has a significant impact on performance on some platforms, > > > but fortunately it seems such a rework can be avoided. > > > > > > There are further bugs in the console code (e.g. that can lead to lost > > > characters) that this series does not address, but those can be fixed > > > separately (and I've started working on that). > > > > I'll take these now, thanks! > > Are you going to continue to work on the driver? There are still some > pretty bad bugs including ones that are affecting Collabora's test > labs. Unless you want to try to tackle it some other way, I'm going to > keep pushing for something like my original series to land. I can > re-post them atop your patches since they've landed. This will regress > your performance but correctness trumps performance. Yes, I have a working fix for the console issue that could lead to lost characters. I need to spend some time on other things this week, but I intend to follow with fixes for the remaining issues as well. Johan
