Zero-copy for STM32 MAC driver.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@4985 35acf78f-673a-0410-8e92-d51de3d6d3f4

2 files changed, 21 insertions, 8 deletions

diff --git a/os/hal/platforms/STM32/mac_lld.c b/os/hal/platforms/STM32/mac_lld.c
index 25a5155ee..9573e991f 100644
--- a/os/hal/platforms/STM32/mac_lld.c
+++ b/os/hal/platforms/STM32/mac_lld.c
@@ -624,18 +624,26 @@ bool_t mac_lld_poll_link_status(MACDriver *macp) {
  *                      on the first call then scale the value down subtracting

  *                      the amount of data already copied into the previous

  *                      buffers.

- * @param[out] sizep    pointer to variable receiving the real buffer size.

- *                      The returned value can be less than the amount

- *                      requested, this means that more buffers must be

- *                      requested in order to fill the frame data entirely.

+ * @param[out] sizep    pointer to variable receiving the buffer size, it is

+ *                      zero when the last buffer has already been returned.

+ *                      Note that a returned size lower than the amount

+ *                      requested means that more buffers must be requested

+ *                      in order to fill the frame data entirely.

  * @return              Pointer to the returned buffer.

+ * @retval NULL         if the buffer chain has been entirely scanned.

  *

  * @notapi

  */

 uint8_t *mac_lld_get_next_transmit_buffer(MACTransmitDescriptor *tdp,

                                           size_t size,

                                           size_t *sizep) {

-  (void)tdp; (void)size; (void)sizep;

+

+  if (tdp->offset == 0) {

+    *sizep      = tdp->size;

+    tdp->offset = size;

+    return (uint8_t *)tdp->physdesc->tdes2;

+  }

+  *sizep = 0;

   return NULL;

 }

 

@@ -655,7 +663,14 @@ uint8_t *mac_lld_get_next_transmit_buffer(MACTransmitDescriptor *tdp,
  */

 const uint8_t *mac_lld_get_next_receive_buffer(MACReceiveDescriptor *rdp,

                                                size_t *sizep) {

-  (void)rdp; (void)sizep;

+

+  if (rdp->size > 0) {

+    *sizep      = rdp->size;

+    rdp->offset = rdp->size;

+    rdp->size   = 0;

+    return (uint8_t *)rdp->physdesc->rdes2;

+  }

+  *sizep = 0;

   return NULL;

 }

 #endif /* MAC_USE_ZERO_COPY */

diff --git a/os/hal/platforms/STM32/mac_lld.h b/os/hal/platforms/STM32/mac_lld.h
index 59c39ac17..f765f1699 100644
--- a/os/hal/platforms/STM32/mac_lld.h
+++ b/os/hal/platforms/STM32/mac_lld.h
@@ -291,7 +291,6 @@ typedef struct {
    * @brief Available space size.

    */

   size_t                    size;

-  /* End of the mandatory fields.*/

   /**

    * @brief Pointer to the physical descriptor.

    */

@@ -310,7 +309,6 @@ typedef struct {
    * @brief Available data size.

    */

   size_t                size;

-  /* End of the mandatory fields.*/

   /**

    * @brief Pointer to the physical descriptor.

    */