Commit ac4ac788 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

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: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent b74d2807

arch/powerpc/platforms/powernv/opal.c

+7 −5
Original line number Diff line number Diff line
@@ -400,11 +400,13 @@ 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.

	 */

	if (written == -EAGAIN)

		opal_flush_console(vtermno);



	return written;

drivers/tty/hvc/hvc_opal.c

+5 −0
Original line number Diff line number Diff line
@@ -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);

}

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