Commit 027f55e8 authored by Nathan Lynch's avatar Nathan Lynch Committed by Michael Ellerman
Browse files

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: default avatarNathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210514214422.3019105-1-nathanl@linux.ibm.com
parent 2cec178e

drivers/tty/hvc/hvc_vio.c

+1 −1
Original line number Diff line number Diff line
@@ -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)