From e00da0f2db91b90e990cc05088f03adbc58af895 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:47 +1000 Subject: [PATCH] powerpc/powernv: opal-kmsg use flush fallback from console code Use the more refined and tested event polling loop from opal_put_chars as the fallback console flush in the opal-kmsg path. This loop is used by the console driver today, whereas the opal-kmsg fallback is not likely to have been used for years. Use WARN_ONCE rather than a printk when the fallback is invoked to prepare for moving the console flush into a common function. Reviewed-by: Russell Currey Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/powernv/opal-kmsg.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/platforms/powernv/opal-kmsg.c b/arch/powerpc/platforms/powernv/opal-kmsg.c index f8f41ccce75f..fd2bbf4fd6dc 100644 --- a/arch/powerpc/platforms/powernv/opal-kmsg.c +++ b/arch/powerpc/platforms/powernv/opal-kmsg.c @@ -51,20 +51,17 @@ static void force_opal_console_flush(struct kmsg_dumper *dumper, } while (rc == OPAL_PARTIAL); /* More to flush */ } else { - int i; + __be64 evt; + WARN_ONCE(1, "opal: OPAL_CONSOLE_FLUSH missing.\n"); /* * If OPAL_CONSOLE_FLUSH is not implemented in the firmware, * the console can still be flushed by calling the polling - * function enough times to flush the buffer. We don't know - * how much output still needs to be flushed, but we can be - * generous since the kernel is in panic and doesn't need - * to do much else. + * function while it has OPAL_EVENT_CONSOLE_OUTPUT events. */ - printk(KERN_NOTICE "opal: OPAL_CONSOLE_FLUSH missing.\n"); - for (i = 0; i < 1024; i++) { - opal_poll_events(NULL); - } + do { + opal_poll_events(&evt); + } while (be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT); } }