From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Arnd Bergmann <arnd@arndb.de>
Cc: linux-kernel@vger.kernel.org,
Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: [PATCH 3/5] char: lp: use first unused lp number while registering
Date: Fri, 7 Dec 2018 14:27:32 +0000 [thread overview]
Message-ID: <20181207142734.27370-3-sudipm.mukherjee@gmail.com> (raw)
In-Reply-To: <20181207142734.27370-1-sudipm.mukherjee@gmail.com>
When the parallel port is usb based and the lp attaches to it based on
LP_PARPORT_AUTO, we do get /dev/lp0 and when we remove the usb device
/dev/lp0 is unregistered. But if we now reconnect the usb device we get
/dev/lp1, another disconnection and reconnection and we get /dev/lp2.
Use the port number array to find the first unused lp number and use
that to register the lp device with the parallel port.
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
drivers/char/lp.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index e21ed4007d0f..0e081f521f51 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -958,7 +958,11 @@ static void lp_attach(struct parport *port)
printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
return;
}
- if (!lp_register(lp_count, port))
+ for (i = 0; i < LP_NO; i++)
+ if (port_num[i] == -1)
+ break;
+
+ if (!lp_register(i, port))
lp_count++;
break;
--
2.11.0
next prev parent reply other threads:[~2018-12-07 14:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-07 14:27 [PATCH 1/5] char: lp: introduce list to save port number Sudip Mukherjee
2018-12-07 14:27 ` [PATCH 2/5] char: lp: detach the device when parallel port is removed Sudip Mukherjee
2018-12-07 14:27 ` Sudip Mukherjee [this message]
2018-12-07 14:27 ` [PATCH 4/5] char: lp: properly count the lp devices Sudip Mukherjee
2018-12-07 14:27 ` [PATCH 5/5] char: lp: use new parport device model Sudip Mukherjee
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