[PATCH] comx-hw-mixcom.c interrupt flag cleanup (244-ac18)

From: Rasmus Andersen (rasmus@jaquet.dk)
Date: Sat May 26 2001 - 16:40:52 EST

(Forgot l-k when sending this off to gorgo@itc.hu :/)

Hi.

The following patch tries to eliminate the interrupt flag bugs
identified by the stanford team a while back in drivers/net/wan/
comx-hw-mixcom.c. It moves request_region and request_irq outside
the cli()/restore_flags() pair as they can sleep and cleans up
some error paths wrt. resource deallocation. It applies against
244-ac18.

Comments would be nice as this is not my day job :)

--- linux-244-ac18-clean/drivers/net/wan/comx-hw-mixcom.c Mon Dec 11 22:38:29 2000
+++ linux-244-ac18/drivers/net/wan/comx-hw-mixcom.c Sat May 26 22:45:44 2001
@@ -487,15 +487,18 @@
         struct mixcom_privdata *hw = ch->HW_privdata;
         struct proc_dir_entry *procfile = ch->procdir->subdir;
         unsigned long flags;
+ int ret = -ENODEV;
 
- if (!dev->base_addr || !dev->irq) return -ENODEV;
+ if (!dev->base_addr || !dev->irq)
+ goto err_ret;
 
 
         if(hw->channel==1) {
                 if(!TWIN(dev) || !(COMX_CHANNEL(TWIN(dev))->init_status &
                     IRQ_ALLOCATED)) {
                         printk(KERN_ERR "%s: channel 0 not yet initialized\n",dev->name);
- return -EAGAIN;
+ ret = -EAGAIN;
+ goto err_ret;
                 }
         }
 
@@ -503,28 +506,29 @@
         /* Is our hw present at all ? Not checking for channel 0 if it is already
            open */
         if(hw->channel!=0 || !(ch->init_status & IRQ_ALLOCATED)) {
- if (check_region(dev->base_addr, MIXCOM_IO_EXTENT)) {
- return -EAGAIN;
+ if (!request_region(dev->base_addr, MIXCOM_IO_EXTENT, dev->name)) {
+ ret = -EAGAIN;
+ goto err_ret;
                 }
                 if (mixcom_probe(dev)) {
- return -ENODEV;
+ ret = -ENODEV;
+ goto err_release_region;
                 }
         }
 
- save_flags(flags); cli();
-
- if(hw->channel==1) {
- request_region(dev->base_addr, MIXCOM_IO_EXTENT, dev->name);
- }
-
         if(hw->channel==0 && !(ch->init_status & IRQ_ALLOCATED)) {
                 if (request_irq(dev->irq, MIXCOM_interrupt, 0,
                     dev->name, (void *)dev)) {
                         printk(KERN_ERR "MIXCOM: unable to obtain irq %d\n", dev->irq);
- return -EAGAIN;
+ ret = -EAGAIN;
+ goto err_restore_flags;
                 }
+ }
+
+ save_flags(flags); cli();
+
+ if(hw->channel==0 && !(ch->init_status & IRQ_ALLOCATED)) {
                 ch->init_status|=IRQ_ALLOCATED;
- request_region(dev->base_addr, MIXCOM_IO_EXTENT, dev->name);
                 mixcom_board_on(dev);
         }
 
@@ -560,6 +564,13 @@
         }
 
         return 0;
+
+err_restore_flags:
+ restore_flags(flags);
+err_release_region:
+ release_region(dev->base_addr, MIXCOM_IO_EXTENT);
+err_ret:
+ return ret;
 }
 
 static int MIXCOM_close(struct net_device *dev) 

-- 
        Rasmus(rasmus@jaquet.dk)

"I'm not going to have some reporters pawing through our papers. We are
the president."  -Hillary Clinton commenting on the release of subpoenaed
documents.
-
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This archive was generated by hypermail 2b29 : Thu May 31 2001 - 21:00:29 EST