[PATCH V2] tty/n_gsm.c: use gsm->num to remove mux itself from gsm_mux[]

[PATCH V2] tty/n_gsm.c: use gsm->num to remove mux itself from gsm_mux[]

[Pan Xinhui]

From: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>

There is one filed gsm->num to store mux's index of gsm_mux[]. So use
gsm->num to remove itself from gsm_mux[] instead of the for-loop
traverse in gsm_cleanup_mux().

Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
change from V1:
	lock is also held for the if()
---
 drivers/tty/n_gsm.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 9aff371..697b31e 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2038,16 +2038,13 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm)
 	gsm->dead = 1;
 
 	spin_lock(&gsm_mux_lock);
-	for (i = 0; i < MAX_MUX; i++) {
-		if (gsm_mux[i] == gsm) {
-			gsm_mux[i] = NULL;
-			break;
-		}
-	}
-	spin_unlock(&gsm_mux_lock);
 	/* open failed before registering => nothing to do */
-	if (i == MAX_MUX)
+	if (gsm_mux[gsm->num] != gsm) {
+		spin_unlock(&gsm_mux_lock);
 		return;
+	}
+	gsm_mux[gsm->num] = NULL;
+	spin_unlock(&gsm_mux_lock);
 
 	/* In theory disconnecting DLCI 0 is sufficient but for some
 	   modems this is apparently not the case. */
-- 
1.9.1

Re: [PATCH V2] tty/n_gsm.c: use gsm->num to remove mux itself from gsm_mux[]

[One Thousand Gnomes]

On Tue, 05 Jan 2016 15:42:52 +0800
Pan Xinhui <xinhui@linux.vnet.ibm.com> wrote:

> From: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
> 
> There is one filed gsm->num to store mux's index of gsm_mux[]. So use
> gsm->num to remove itself from gsm_mux[] instead of the for-loop
> traverse in gsm_cleanup_mux().
> 
> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>

Reviewed-by: Alan Cox <alan@linux.intel.com>

Re: [PATCH V2] tty/n_gsm.c: use gsm->num to remove mux itself from gsm_mux[]

[Greg Kroah-Hartman]

On Tue, Jan 05, 2016 at 03:42:52PM +0800, Pan Xinhui wrote:
> From: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
> 
> There is one filed gsm->num to store mux's index of gsm_mux[]. So use
> gsm->num to remove itself from gsm_mux[] instead of the for-loop
> traverse in gsm_cleanup_mux().
> 
> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
> Reviewed-by: Alan Cox <alan@linux.intel.com>
> ---
> change from V1:
> 	lock is also held for the if()
> ---
>  drivers/tty/n_gsm.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)

Doesn't apply to my tty-next branch of the tty.git tree :(

Re: [PATCH V2] tty/n_gsm.c: use gsm->num to remove mux itself from gsm_mux[]

[Pan Xinhui]

hi, Greg
	thanks for your reply.
On 2016/2/7 15:29, Greg Kroah-Hartman wrote:
> On Tue, Jan 05, 2016 at 03:42:52PM +0800, Pan Xinhui wrote:
>> From: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
>>
>> There is one filed gsm->num to store mux's index of gsm_mux[]. So use
>> gsm->num to remove itself from gsm_mux[] instead of the for-loop
>> traverse in gsm_cleanup_mux().
>>
>> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
>> Reviewed-by: Alan Cox <alan@linux.intel.com>
>> ---
>> change from V1:
>> 	lock is also held for the if()
>> ---
>>   drivers/tty/n_gsm.c | 13 +++++--------
>>   1 file changed, 5 insertions(+), 8 deletions(-)
>
> Doesn't apply to my tty-next branch of the tty.git tree :(
>

Sorry for not telling you one important information.
This patch is on top of Jiri's patch, "TTY: n_gsm, fix false positive WARN_ON", see https://patchwork.kernel.org/patch/7692181/
Looks like Jiri's patch is still not in your tree.

Hi, Jiri
	Could I make a new patch on top of the mainline's codes first then you prepare your patch on top of mine?
I will appreciate that if you have a better solution :)


thanks
xinhui