Hi Greg,
Am 2020-02-20 18:46, schrieb Michael Walle:
If a driver exposes early consoles with EARLYCON_DECLARE() and
OF_EARLYCON_DECLARE(), pefer the non-OF variant if the user specifies
it
by
earlycon=<driver>,<options>
The rationale behind this is that some drivers register multiple setup
functions under the same driver name. Eg.
OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart",
lpuart_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart",
lpuart32_early_console_setup);
OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart",
lpuart32_imx_early_console_setup);
EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
It depends on the order of the entries which console_setup() actually
gets called. To make things worse, I guess it also depends on the
compiler how these are ordered. Thus always prefer the
EARLYCON_DECLARE()
ones.
Do you have an opinon on this proposal?
-michael
Signed-off-by: Michael Walle <michael@xxxxxxxx>
---
drivers/tty/serial/earlycon.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/tty/serial/earlycon.c
b/drivers/tty/serial/earlycon.c
index c14873b67803..2ae9190b64bb 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -170,6 +170,7 @@ static int __init register_earlycon(char *buf,
const struct earlycon_id *match)
int __init setup_earlycon(char *buf)
{
const struct earlycon_id **p_match;
+ bool empty_compatible = true;
if (!buf || !buf[0])
return -EINVAL;
@@ -177,6 +178,7 @@ int __init setup_earlycon(char *buf)
if (early_con.flags & CON_ENABLED)
return -EALREADY;
+again:
for (p_match = __earlycon_table; p_match < __earlycon_table_end;
p_match++) {
const struct earlycon_id *match = *p_match;
@@ -185,6 +187,10 @@ int __init setup_earlycon(char *buf)
if (strncmp(buf, match->name, len))
continue;
+ /* prefer entries with empty compatible */
+ if (empty_compatible && *match->compatible)
+ continue;
+
if (buf[len]) {
if (buf[len] != ',')
continue;
@@ -195,6 +201,11 @@ int __init setup_earlycon(char *buf)
return register_earlycon(buf, match);
}
+ if (empty_compatible) {
+ empty_compatible = false;
+ goto again;
+ }
+
return -ENOENT;
}
