[PATCH 1/5] char: lp: introduce list to save port number

From: Sudip Mukherjee
Date: Fri Dec 07 2018 - 09:27:43 EST


When we are registering lp in LP_PARPORT_AUTO mode, we are not keeping
any record of the parallel port number to which lp is connecting.
Add an array to save the port number to it.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
drivers/char/lp.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index e0a92d764eee..7e207ff0f2fe 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -141,6 +141,7 @@

static DEFINE_MUTEX(lp_mutex);
static struct lp_struct lp_table[LP_NO];
+static int port_num[LP_NO];

static unsigned int lp_count = 0;
static struct class *lp_class;
@@ -938,6 +939,7 @@ static int lp_register(int nr, struct parport *port)
CONSOLE_LP, port->name);
}
#endif
+ port_num[nr] = port->number;

return 0;
}
@@ -1013,6 +1015,7 @@ static int __init lp_init(void)
init_waitqueue_head(&lp_table[i].dataq);
mutex_init(&lp_table[i].port_mutex);
lp_table[i].timeout = 10 * HZ;
+ port_num[i] = -1;
}

if (register_chrdev(LP_MAJOR, "lp", &lp_fops)) {
@@ -1091,6 +1094,7 @@ static void lp_cleanup_module(void)
for (offset = 0; offset < LP_NO; offset++) {
if (lp_table[offset].dev == NULL)
continue;
+ port_num[offset] = -1;
parport_unregister_device(lp_table[offset].dev);
device_destroy(lp_class, MKDEV(LP_MAJOR, offset));
}
--
2.11.0