Changeset f7a55f9 in mainline for uspace/drv/bus/usb/usbmast/mast.c

Timestamp:

2011-07-05T10:43:21Z (13 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

5e2aa83, bee37cf

Parents:

b5085a7

Message:

Implement Read and Request Sense commands for USB mass storage. In bulk-only
transport fix case when less data is returned by padding + residue. Add note
for case when less data is returned by stalling the pipe.

File:

• uspace/drv/bus/usb/usbmast/mast.c (modified) (4 diffs)

uspace/drv/bus/usb/usbmast/mast.c

@@ -92 +92 @@
             str_error(rc));
         if (rc != EOK) {
+                /*
+                 * XXX If the pipe is stalled, we should clear it
+                 * and read CSW.
+                 */
                 return rc;
         }
@@ -103 +107 @@
             str_error(rc));
         if (rc != EOK) {
-                return rc;
-        }
+                MASTLOG("rc != EOK\n");
+                return rc;
+        }
+
         if (csw_size != sizeof(csw)) {
+                MASTLOG("csw_size != sizeof(csw)\n");
                 return ERANGE;
         }
 
         if (csw.dCSWTag != tag) {
+                MASTLOG("csw.dCSWTag != tag\n");
                 return EBADCHECKSUM;
         }
@@ -117 +125 @@
          */
         if (csw.dCSWStatus != 0) {
+                MASTLOG("csw.dCSWStatus != 0\n");
                 // FIXME: better error code
                 // FIXME: distinguish 0x01 and 0x02
@@ -124 +133 @@
         size_t residue = (size_t) uint32_usb2host(csw.dCSWDataResidue);
         if (residue > in_buffer_size) {
+                MASTLOG("residue > in_buffer_size\n");
                 return ERANGE;
         }
-        if (act_size != in_buffer_size - residue) {
-                return ERANGE;
-        }
+
+        /*
+         * When the device has less data to send than requested, it can
+         * either stall the pipe or send garbage and indicate that via
+         * the residue field in CSW. That means in_buffer_size - residue
+         * is the authoritative size of data received.
+         */
+
         if (received_size != NULL) {
                 *received_size = in_buffer_size - residue;