diff options
Diffstat (limited to 'drivers/tty/hvc/hvc_vio.c')
| -rw-r--r-- | drivers/tty/hvc/hvc_vio.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c index 6de6d4a1a221..7af54d6ed5b8 100644 --- a/drivers/tty/hvc/hvc_vio.c +++ b/drivers/tty/hvc/hvc_vio.c @@ -107,6 +107,14 @@ static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count) return got; } +/** + * hvterm_raw_put_chars: send characters to firmware for given vterm adapter + * @vtermno: The virtual terminal number. + * @buf: The characters to send. Because of the underlying hypercall in + * hvc_put_chars(), this buffer must be at least 16 bytes long, even if + * you are sending fewer chars. + * @count: number of chars to send. + */ static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count) { struct hvterm_priv *pv = hvterm_privs[vtermno]; @@ -219,6 +227,7 @@ static const struct hv_ops hvterm_hvsi_ops = { static void udbg_hvc_putc(char c) { int count = -1; + unsigned char bounce_buffer[16]; if (!hvterm_privs[0]) return; @@ -229,7 +238,12 @@ static void udbg_hvc_putc(char c) do { switch(hvterm_privs[0]->proto) { case HV_PROTOCOL_RAW: - count = hvterm_raw_put_chars(0, &c, 1); + /* + * hvterm_raw_put_chars requires at least a 16-byte + * buffer, so go via the bounce buffer + */ + bounce_buffer[0] = c; + count = hvterm_raw_put_chars(0, bounce_buffer, 1); break; case HV_PROTOCOL_HVSI: count = hvterm_hvsi_put_chars(0, &c, 1); |