2013-05-14 23:34:51

by Malcolm Priestley

Subject: [PATCH] staging: vt6656: [bug] Fix missing spin lock in iwctl_siwpower.

Fixes occasional dead lock on power up / down.

Only relevant to kernels 3.8 and later when command was
transferred to the iw_handler.

Signed-off-by: Malcolm Priestley <[email protected]>
Cc: [email protected] # 3.8+
---
drivers/staging/vt6656/iwctl.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/staging/vt6656/iwctl.c b/drivers/staging/vt6656/iwctl.c
index c335808..855eb58 100644
--- a/drivers/staging/vt6656/iwctl.c
+++ b/drivers/staging/vt6656/iwctl.c
@@ -1334,6 +1334,7 @@ int iwctl_siwpower(struct net_device *dev, struct iw_request_info *info,
struct vnt_manager *pMgmt = &pDevice->vnt_mgmt;
struct iw_param *wrq = &wrqu->power;
int rc = 0;
+ unsigned long flags;

DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO " SIOCSIWPOWER\n");

@@ -1345,9 +1346,12 @@ int iwctl_siwpower(struct net_device *dev, struct iw_request_info *info,
return rc;
}

+ spin_lock_irqsave(&pDevice->lock, flags);
+
if (wrq->disabled) {
pDevice->ePSMode = WMAC_POWER_CAM;
PSvDisablePowerSaving(pDevice);
+ spin_unlock_irqrestore(&pDevice->lock, flags);
return rc;
}
if ((wrq->flags & IW_POWER_TYPE) == IW_POWER_TIMEOUT) {
@@ -1358,6 +1362,9 @@ int iwctl_siwpower(struct net_device *dev, struct iw_request_info *info,
pDevice->ePSMode = WMAC_POWER_FAST;
PSvEnablePowerSaving((void *)pDevice, pMgmt->wListenInterval);
}
+
+ spin_unlock_irqrestore(&pDevice->lock, flags);
+
switch (wrq->flags & IW_POWER_MODE) {
case IW_POWER_UNICAST_R:
DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO " SIOCSIWPOWER: IW_POWER_UNICAST_R \n");
--
1.8.1.2

2013-05-15 00:12:19

by Malcolm Priestley

Subject: Re: [PATCH] staging: vt6656: [bug] Fix missing spin lock in iwctl_siwpower.

On Wed, 2013-05-15 at 00:34 +0100, Malcolm Priestley wrote:
> Fixes occasional dead lock on power up / down.
>
> Only relevant to kernels 3.8 and later when command was
> transferred to the iw_handler.
>

Please ignore this patch, I will redo, I shouldn't have used
spin_lock_irqsave.

Malcolm