mos7720 update
this driver has an interesting way of handling ENOMEM: complain and ignore.
If you decide to live with allocation failures, you must
1. guard against URBs without corresponding buffers
2. complete allocation failures
3. always test entries for NULL before you follow the pointers
This patch does so.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index 4538dc3..6ba87e6 100644
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -333,6 +333,7 @@
int response;
int port_number;
char data;
+ int allocated_urbs = 0;
int j;
serial = port->serial;
@@ -365,10 +366,16 @@
GFP_KERNEL);
if (!urb->transfer_buffer) {
err("%s-out of memory for urb buffers.", __FUNCTION__);
+ usb_free_urb(mos7720_port->write_urb_pool[j]);
+ mos7720_port->write_urb_pool[j] = NULL;
continue;
}
+ allocated_urbs++;
}
+ if (!allocated_urbs)
+ return -ENOMEM;
+
/* Initialize MCS7720 -- Write Init values to corresponding Registers
*
* Register Index
@@ -526,7 +533,7 @@
}
for (i = 0; i < NUM_URBS; ++i) {
- if (mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
+ if (mos7720_port->write_urb_pool[i] && mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
chars += URB_TRANSFER_BUFFER_SIZE;
}
dbg("%s - returns %d", __FUNCTION__, chars);
@@ -629,7 +636,7 @@
}
for (i = 0; i < NUM_URBS; ++i) {
- if (mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
+ if (mos7720_port->write_urb_pool[i] && mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
room += URB_TRANSFER_BUFFER_SIZE;
}
@@ -664,7 +671,7 @@
urb = NULL;
for (i = 0; i < NUM_URBS; ++i) {
- if (mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
+ if (mos7720_port->write_urb_pool[i] && mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
urb = mos7720_port->write_urb_pool[i];
dbg("URB:%d",i);
break;