[PATCH] USB: cdc-acm: add a new special case for modems with buggy firmware
this fixes the "duplicated text" bug. There's a modem that cannot cope
with large transfers and more than one urb in flight. This patch adds a
special case to the driver.
Signed-off-by: Oliver Neukum <oliver@neukum.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index fd2aaccd..1bcaea3 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -56,11 +56,11 @@
* in line disciplines. They ask for empty space amount, receive our URB size,
* and proceed to issue several 1-character writes, assuming they will fit.
* The very first write takes a complete URB. Fortunately, this only happens
- * when processing onlcr, so we only need 2 buffers.
+ * when processing onlcr, so we only need 2 buffers. These values must be
+ * powers of 2.
*/
-#define ACM_NWB 2
-#define ACM_NRU 16
-#define ACM_NRB 16
+#define ACM_NW 2
+#define ACM_NR 16
struct acm_wb {
unsigned char *buf;
@@ -91,9 +91,10 @@
struct urb *ctrlurb, *writeurb; /* urbs */
u8 *ctrl_buffer; /* buffers of urbs */
dma_addr_t ctrl_dma; /* dma handles of buffers */
- struct acm_wb wb[ACM_NWB];
- struct acm_ru ru[ACM_NRU];
- struct acm_rb rb[ACM_NRB];
+ struct acm_wb wb[ACM_NW];
+ struct acm_ru ru[ACM_NR];
+ struct acm_rb rb[ACM_NR];
+ int rx_buflimit;
int rx_endpoint;
spinlock_t read_lock;
struct list_head spare_read_urbs;
@@ -122,3 +123,4 @@
/* constants describing various quirks and errors */
#define NO_UNION_NORMAL 1
+#define SINGLE_RX_URB 2
