diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2018-05-01 00:55:50 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-07-24 22:09:57 +1000 |
| commit | ac4ac788fdadc6b703ff3322de07dee442e08e1c (patch) | |
| tree | ea1fbf4f4ec19a771adf1c7ce42272cd12aea3ab | |
| parent | b74d2807ae0cdb17ccc45d22260fc151a1b2d46b (diff) | |
| download | linux-ac4ac788fdadc6b703ff3322de07dee442e08e1c.tar.bz2 | |
powerpc/powernv: move opal console flushing to udbg
OPAL console writes do not have to synchronously flush firmware /
hardware buffers unless they are going through the udbg path.
Remove the unconditional flushing from opal_put_chars. Flush if
there was no space in the buffer as an optimisation (callers loop
waiting for success in that case). udbg flushing is moved to
udbg_opal_putc.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal.c | 12 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_opal.c | 5 |
2 files changed, 12 insertions, 5 deletions
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index e18472757617..cf02e602237a 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -400,12 +400,14 @@ int opal_put_chars(uint32_t vtermno, const char *data, int total_len) out: spin_unlock_irqrestore(&opal_write_lock, flags); - /* This is a bit nasty but we need that for the console to - * flush when there aren't any interrupts. We will clean - * things a bit later to limit that to synchronous path - * such as the kernel console and xmon/udbg + /* In the -EAGAIN case, callers loop, so we have to flush the console + * here in case they have interrupts off (and we don't want to wait + * for async flushing if we can make immediate progress here). If + * necessary the API could be made entirely non-flushing if the + * callers had a ->flush API to use. */ - opal_flush_console(vtermno); + if (written == -EAGAIN) + opal_flush_console(vtermno); return written; } diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c index 9645c0062a90..958c61c8f35a 100644 --- a/drivers/tty/hvc/hvc_opal.c +++ b/drivers/tty/hvc/hvc_opal.c @@ -275,6 +275,11 @@ static void udbg_opal_putc(char c) count = hvc_opal_hvsi_put_chars(termno, &c, 1); break; } + + /* This is needed for the cosole to flush + * when there aren't any interrupts. + */ + opal_flush_console(termno); } while(count == 0 || count == -EAGAIN); } |