playback,talk: Share audiobuffer via core_alloc_maximum().

This fixes the radioart crash that was the result of buffering.c working
on a freed buffer at the same time as buflib (radioart uses buffering.c for the
images). With this change the buffer is owned by buflib exclusively so this
cannot happen.

As a result, audio_get_buffer() doesn't exist anymore. Callers should call
core_alloc_maximum() directly. This buffer needs to be protected as usual
against movement if necessary (previously it was not protected at all which
cased the radioart crash), To get most of it they can adjust the willingness of
the talk engine to give its buffer away (at the expense of disabling voice
interface) with the new talk_buffer_set_policy() function.

Change-Id: I52123012208d04967876a304451d634e2bef3a33

1 files changed, 12 insertions, 5 deletions

diff --git a/firmware/usbstack/usb_storage.c b/firmware/usbstack/usb_storage.c
index d1279d0ee1..a3b867319d 100644
--- a/firmware/usbstack/usb_storage.c
+++ b/firmware/usbstack/usb_storage.c
@@ -34,6 +34,7 @@
 #if CONFIG_RTC
 #include "timefuncs.h"
 #endif
+#include "core_alloc.h"
 
 #ifdef USB_USE_RAMDISK
 #define RAMDISK_SIZE 2048
@@ -430,6 +431,7 @@ int usb_storage_get_config_descriptor(unsigned char *dest,int max_packet_size)
     return (dest - orig_dest);
 }
 
+static int usb_handle;
 void usb_storage_init_connection(void)
 {
     logf("ums: set config");
@@ -452,13 +454,17 @@ void usb_storage_init_connection(void)
 #else
     /* TODO : check if bufsize is at least 32K ? */
     size_t bufsize;
-    unsigned char * audio_buffer;
+    unsigned char * buffer;
+    /* dummy ops with no callbacks, needed because by
+     * default buflib buffers can be moved around which must be avoided */
+    static struct buflib_callbacks dummy_ops;
 
-    audio_buffer = audio_get_buffer(false,&bufsize);
+    usb_handle = core_alloc_maximum("usb storage", &bufsize, &dummy_ops);
+    buffer = core_get_data(usb_handle);
 #if defined(UNCACHED_ADDR) && CONFIG_CPU != AS3525
-    cbw_buffer = (void *)UNCACHED_ADDR((unsigned int)(audio_buffer+31) & 0xffffffe0);
+    cbw_buffer = (void *)UNCACHED_ADDR((unsigned int)(buffer+31) & 0xffffffe0);
 #else
-    cbw_buffer = (void *)((unsigned int)(audio_buffer+31) & 0xffffffe0);
+    cbw_buffer = (void *)((unsigned int)(buffer+31) & 0xffffffe0);
 #endif
     tb.transfer_buffer = cbw_buffer + MAX_CBW_SIZE;
     commit_discard_dcache();
@@ -478,7 +484,8 @@ void usb_storage_init_connection(void)
 
 void usb_storage_disconnect(void)
 {
-    /* Empty for now */
+    if (usb_handle > 0)
+        usb_handle = core_free(usb_handle);
 }
 
 /* called by usb_core_transfer_complete() */