Merge pull request adafruit#425 from tannewt/align_usb

atmel-samd: USB mass storage tweaks.

Author: dhalbert

ports/atmel-samd/asf4_conf/samd51/hpl_nvmctrl_config.h

@@ -19,14 +19,14 @@
 // <i> Indicate whether AHB0 cache is disable or not
 // <id> nvm_arch_cache0
 #ifndef CONF_NVM_CACHE0
-#define CONF_NVM_CACHE0 0
+#define CONF_NVM_CACHE0 1
 #endif
 
 // <q> AHB1 Cache Disable
 // <i> Indicate whether AHB1 cache is disable or not
 // <id> nvm_arch_cache1
 #ifndef CONF_NVM_CACHE1
-#define CONF_NVM_CACHE1 0
+#define CONF_NVM_CACHE1 1
 #endif
 
 // </h>

ports/atmel-samd/usb_mass_storage.c

@@ -63,10 +63,10 @@ static fs_user_mount_t* get_vfs(int lun) {
 /* Inquiry Information */
 // This is designed to handle the common case where we have an internal file
 // system and an optional SD card.
-static uint8_t inquiry_info[2][36];
+COMPILER_ALIGNED(4) static uint8_t inquiry_info[2][36];
 
 /* Capacities of Disk */
-static uint8_t format_capa[2][8];
+COMPILER_ALIGNED(4) static uint8_t format_capa[2][8];
 
 /**
  * \brief Eject Disk
@@ -256,30 +256,34 @@ int32_t usb_msc_xfer_done(uint8_t lun) {
  return ERR_DENIED;
  }
 
+ CRITICAL_SECTION_ENTER();
  if (active_read) {
  active_addr += 1;
  active_nblocks--;
- if (active_nblocks == 0) {
- active_read = false;
- }
  }
 
  if (active_write) {
  sector_loaded = true;
  }
  usb_busy = false;
+ CRITICAL_SECTION_LEAVE();
 
  return ERR_NONE;
 }
 
 // The start_read callback begins a read transaction which we accept but delay our response until the "main thread" calls usb_msc_background. Once it does, we read immediately from the drive into our cache and trigger the USB DMA to output the sector. Once the sector is transmitted, xfer_done will be called.
 void usb_msc_background(void) {
  if (active_read && !usb_busy) {
+ if (active_nblocks == 0) {
+ active_read = false;
+ return;
+ }
  fs_user_mount_t * vfs = get_vfs(active_lun);
  disk_read(vfs, sector_buffer, active_addr, 1);
- // TODO(tannewt): Check the read result.
- mscdf_xfer_blocks(true, sector_buffer, 1);
- usb_busy = true;
+ CRITICAL_SECTION_ENTER();
+ int32_t result = mscdf_xfer_blocks(true, sector_buffer, 1);
+ usb_busy = result == ERR_NONE;
+ CRITICAL_SECTION_LEAVE();
  }
  if (active_write && !usb_busy) {
  if (sector_loaded) {
@@ -306,8 +310,14 @@ void usb_msc_background(void) {
  }
  // Load more blocks from USB if they are needed.
  if (active_nblocks > 0) {
+ // Turn off interrupts because with them on,
+ // usb_msc_xfer_done could be called before we update
+ // usb_busy. If that happened, we'd overwrite the fact that
+ // the transfer actually already finished.
+ CRITICAL_SECTION_ENTER();
  int32_t result = mscdf_xfer_blocks(false, sector_buffer, 1);
- usb_busy = result != ERR_NONE;
+ usb_busy = result == ERR_NONE;
+ CRITICAL_SECTION_LEAVE();
  } else {
  mscdf_xfer_blocks(false, NULL, 0);
  active_write = false;