On Sat, Jan 16, 2010 at 8:16 AM, Blue Swirl <blauwir...@gmail.com> wrote: > On Fri, Jan 15, 2010 at 10:37 PM, Artyom Tarasenko > <atar4q...@googlemail.com> wrote: >> Don't clear interrupts on disabling, because >> * Sun4M_SystemArchitecture_edited2.pdf doesn't describe >> that masking or un-masking IRQ shall clear pending ones. >> >> * Field tests also show that SPARCstation-20 doesn't >> clear them. > > Awesome work! > >> * The patch makes Solaris 2.5.1/2.6 boot ~1500 times >> faster (~20 seconds instead of ~8 hours) > > Unfortunately there is some problem with the patch (or more likely > there is some other bug that this uncovers), because all my Linux test > now panic. NetBSD and OpenBSD are unaffected. > > For example, sparc-test: > eth0: LANCE 52:54:00:12:34:56 > esp0: no command in esp_handle() > Kernel panic - not syncing: esp_handle: current_SC == penguin within > interrupt! > <0>Press L1-A to return to the boot prom > > The bug may be in ESP interrupt handling (or in the interrupt chain > between ESP, DMA controller and interrupt controller) as the panic > always happens in ESP probe.
In fact the bug was that OpenBIOS didn't clear ESP interrupts after issuing commands, so the IRQ line was left raised which confused Linux.
