From 027f55e87c3094270a3223f7331d033fe15a2b3f Mon Sep 17 00:00:00 2001 From: Nathan Lynch Date: Fri, 14 May 2021 16:44:22 -0500 Subject: tty: hvc: udbg_hvc: retry putc on -EAGAIN hvterm_raw_put_chars() calls hvc_put_chars(), which may return -EAGAIN when the underlying hcall returns a "busy" status, but udbg_hvc_putc() doesn't handle this. When using xmon on a PowerVM guest, this can result in incomplete or garbled output when printing relatively large amounts of data quickly, such as when dumping the kernel log buffer. Call again on -EAGAIN. Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210514214422.3019105-1-nathanl@linux.ibm.com --- drivers/tty/hvc/hvc_vio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c index 798f27f40cc2..72b11aa7e0a6 100644 --- a/drivers/tty/hvc/hvc_vio.c +++ b/drivers/tty/hvc/hvc_vio.c @@ -249,7 +249,7 @@ static void udbg_hvc_putc(char c) count = hvterm_hvsi_put_chars(0, &c, 1); break; } - } while(count == 0); + } while (count == 0 || count == -EAGAIN); } static int udbg_hvc_getc_poll(void) -- cgit