From f083b807001156784b2bf59ee7e0fce54da33951 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 12 Jul 2018 13:12:21 +1000
Subject: [PATCH] HAL_ChibiOS: added preallocation of DMA bouncebuffers

we need 512 bytes for microSD
---
 libraries/AP_HAL_ChibiOS/Device.cpp                  | 4 ++--
 libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.c | 7 ++++++-
 libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.h | 2 +-
 libraries/AP_HAL_ChibiOS/sdcard.cpp                  | 2 +-
 4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/libraries/AP_HAL_ChibiOS/Device.cpp b/libraries/AP_HAL_ChibiOS/Device.cpp
index 4c51a5efe9..f0b6779626 100644
--- a/libraries/AP_HAL_ChibiOS/Device.cpp
+++ b/libraries/AP_HAL_ChibiOS/Device.cpp
@@ -31,8 +31,8 @@ static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
 DeviceBus::DeviceBus(uint8_t _thread_priority) :
         thread_priority(_thread_priority)
 {
-    bouncebuffer_init(&bounce_buffer_tx);
-    bouncebuffer_init(&bounce_buffer_rx);
+    bouncebuffer_init(&bounce_buffer_tx, 10);
+    bouncebuffer_init(&bounce_buffer_rx, 10);
 }
 
 /*
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.c b/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.c
index 4ef1483361..bd7577fd2f 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.c
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.c
@@ -32,10 +32,15 @@
 /*
   initialise a bouncebuffer
  */
-void bouncebuffer_init(struct bouncebuffer_t **bouncebuffer)
+void bouncebuffer_init(struct bouncebuffer_t **bouncebuffer, uint32_t prealloc_bytes)
 {
     (*bouncebuffer) = calloc(1, sizeof(struct bouncebuffer_t));
     osalDbgAssert(((*bouncebuffer) != NULL), "bouncebuffer init");
+    if (prealloc_bytes) {
+        (*bouncebuffer)->dma_buf = malloc_dma(prealloc_bytes);
+        osalDbgAssert(((*bouncebuffer)->dma_buf != NULL), "bouncebuffer preallocate");
+        (*bouncebuffer)->size = prealloc_bytes;
+    }
 }
 
 /*
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.h b/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.h
index a3704884a6..da78234c7e 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.h
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.h
@@ -21,7 +21,7 @@ struct bouncebuffer_t {
 /*
   initialise a bouncebuffer
  */
-void bouncebuffer_init(struct bouncebuffer_t **bouncebuffer);
+void bouncebuffer_init(struct bouncebuffer_t **bouncebuffer, uint32_t prealloc_bytes);
 
 /*
   setup for reading from a device into memory, allocating a bouncebuffer if needed
diff --git a/libraries/AP_HAL_ChibiOS/sdcard.cpp b/libraries/AP_HAL_ChibiOS/sdcard.cpp
index 5721767c48..3c1e26f117 100644
--- a/libraries/AP_HAL_ChibiOS/sdcard.cpp
+++ b/libraries/AP_HAL_ChibiOS/sdcard.cpp
@@ -46,7 +46,7 @@ void sdcard_init()
     sdcard_init_done = true;
 #if HAL_USE_SDC
 
-    bouncebuffer_init(&SDCD1.bouncebuffer);
+    bouncebuffer_init(&SDCD1.bouncebuffer, 512);
     
     sdcStart(&SDCD1, NULL);