Since commit d6713b4091a99fa2af2fabdcd2f3fb97f32ecf2e ("m68k: early
parameter support"), the user can specify multiple debug consoles using the
"debug=" kernel command line parameter.
However, as the struct console object was shared, it would actually register
the same console object multiple times, causing the following warning:WARNING: CPU: 0 PID: 0 at kernel/printk/printk.c:2233 register_console+0x36/0x2b6() console 'debug0' already registered Note that only the console corresponding to the last "debug=" parameter became active, as the .write() method was overwritten before registration. Use separate console objects to allow using multiple debug consoles. Signed-off-by: Geert Uytterhoeven <[email protected]> --- Notes: 1. This patch was only compile-tested. 2. Do we want to fix it this way? Alternatives are: a. Reject a second debug= parameter by checking for a non-NULL .write() method => only the first debug console will be used, b. Skip console registration in case of a non-NULL .write() method => only the last debug console will be used, 3. Atari has a similar issue, with even more (4) debug consoles. arch/m68k/amiga/config.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/arch/m68k/amiga/config.c b/arch/m68k/amiga/config.c index 049ef8605314..b975eefba30f 100644 --- a/arch/m68k/amiga/config.c +++ b/arch/m68k/amiga/config.c @@ -107,12 +107,6 @@ static void amiga_mem_console_write(struct console *co, const char *b, static void amiga_heartbeat(int on); #endif -static struct console amiga_console_driver = { - .name = "debug", - .flags = CON_PRINTBUFFER, - .index = -1, -}; - /* * Motherboard Resources present in all Amiga models @@ -624,6 +618,13 @@ static void amiga_mem_console_write(struct console *co, const char *s, } } +static struct console amiga_mem_console = { + .name = "debug", + .write = amiga_mem_console_write, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + static int __init amiga_savekmsg_setup(char *arg) { if (!MACH_IS_AMIGA || strcmp(arg, "mem")) @@ -642,8 +643,7 @@ static int __init amiga_savekmsg_setup(char *arg) savekmsg->magicptr = ZTWO_PADDR(savekmsg); savekmsg->size = 0; - amiga_console_driver.write = amiga_mem_console_write; - register_console(&amiga_console_driver); + register_console(&amiga_mem_console); return 0; } @@ -723,12 +723,18 @@ void amiga_serial_gets(struct console *co, char *s, int len) } #endif +static struct console amiga_serial_console = { + .name = "debug", + .write = amiga_serial_console_write, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + static int __init amiga_debug_setup(char *arg) { if (MACH_IS_AMIGA && !strcmp(arg, "ser")) { /* no initialization required (?) */ - amiga_console_driver.write = amiga_serial_console_write; - register_console(&amiga_console_driver); + register_console(&amiga_serial_console); } return 0; } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
