From ac16594d2aa1d86b3216ddc40a3526f20152177b Mon Sep 17 00:00:00 2001
From: Cristian Maglie <c.maglie@arduino.cc>
Date: Thu, 10 Sep 2015 16:08:32 +0200
Subject: [PATCH] Disabled SRAM shortcut when in USBCore::send
The shortcut has some issues:
- sometimes it fails when sending an odd number of bytes (may be
due to memory alignment?)
- the data pointer should point to "stable" data (and this is not
guaranteed by caller, it may be some sort of temporary buffer)
- the SRAM is not guaranteed to start at 0x20000000
All the above problems must be properly fixed before reenabling
this part
---
cores/arduino/USB/USBCore.cpp | 57 ++++++++++++++++++++---------------
1 file changed, 33 insertions(+), 24 deletions(-)
diff --git a/cores/arduino/USB/USBCore.cpp b/cores/arduino/USB/USBCore.cpp
index 99009e83..d40662f0 100644
--- a/cores/arduino/USB/USBCore.cpp
+++ b/cores/arduino/USB/USBCore.cpp
@@ -565,6 +565,17 @@ uint32_t USBDeviceClass::send(uint32_t ep, const void *data, uint32_t len)
if (len > 16384)
return -1;
+#if 0
+// This shortcut has some issues:
+// - sometimes it fails when sending an odd number of bytes (may be
+// due to memory alignment?)
+// - the data pointer should point to "stable" data (and this is not
+// guaranteed by caller, it may be some sort of temporary buffer)
+// - the SRAM is not guaranteed to start at 0x20000000
+
+// All the above problems must be properly fixed before reenabling
+// this part
+
if ((unsigned int)data > 0x20000000)
{
// Buffer in RAM
@@ -583,39 +594,37 @@ uint32_t USBDeviceClass::send(uint32_t ep, const void *data, uint32_t len)
while (!usbd.epBank1IsTransferComplete(ep)) {
; // need fire exit.
}
- len = 0;
+ return 0;
}
- else
+#endif
+
+ // Flash area
+ while (len != 0)
{
- // Flash area
- while (len != 0)
- {
- if (len >= 64) {
- length = 64;
- } else {
- length = len;
- }
+ if (len >= 64) {
+ length = 64;
+ } else {
+ length = len;
+ }
- /* memcopy could be safer in multi threaded environment */
- memcpy(&udd_ep_in_cache_buffer[ep], data, length);
+ /* memcopy could be safer in multi threaded environment */
+ memcpy(&udd_ep_in_cache_buffer[ep], data, length);
- usbd.epBank1SetAddress(ep, &udd_ep_in_cache_buffer[ep]);
- usbd.epBank1SetByteCount(ep, length);
+ usbd.epBank1SetAddress(ep, &udd_ep_in_cache_buffer[ep]);
+ usbd.epBank1SetByteCount(ep, length);
- // Clear the transfer complete flag
- usbd.epBank1AckTransferComplete(ep);
+ // Clear the transfer complete flag
+ usbd.epBank1AckTransferComplete(ep);
- // RAM buffer is full, we can send data (IN)
- usbd.epBank1SetReady(ep);
+ // RAM buffer is full, we can send data (IN)
+ usbd.epBank1SetReady(ep);
- // Wait for transfer to complete
- while (!usbd.epBank1IsTransferComplete(ep)) {
- ; // need fire exit.
- }
- len -= length;
+ // Wait for transfer to complete
+ while (!usbd.epBank1IsTransferComplete(ep)) {
+ ; // need fire exit.
}
+ len -= length;
}
-
return len;
}
--
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