px4_autopilot/nuttx-patches/00033-BACKPORT-stm32f7-sdmmc-dcache-fix.patch

diff --git NuttX/nuttx/arch/arm/src/stm32f7/stm32_dma.c NuttX/nuttx/arch/arm/src/stm32f7/stm32_dma.c
index a695a07..1d54daf 100644
--- NuttX/nuttx/arch/arm/src/stm32f7/stm32_dma.c
+++ NuttX/nuttx/arch/arm/src/stm32f7/stm32_dma.c
@@ -860,6 +860,13 @@ size_t stm32_dmaresidual(DMA_HANDLE handle)
  *   of the processor. Note that this only applies to memory addresses, it
  *   will return false for any peripheral address.
  *
+ * Input Parameters:
+ *
+ *   maddr - starting memory address
+ *   count - number of unit8 or uint16 or uint32 items as defined by MSIZE of
+ *           ccr.
+ *   ccr   - DMA stream configuration register
+ *
  * Returned value:
  *   True, if transfer is possible.
  *
@@ -877,7 +884,8 @@ bool stm32_dmacapable(uint32_t maddr, uint32_t count, uint32_t ccr)
    * Transfers to/from memory performed by the DMA controller are
    * required to be aligned to their size.
    *
-   * See ST RM0090 rev4, section 9.3.11
+   * See ST RM0410 DocID028270 Rev 2, section 8.3.11 Single and burst
+   * transfers
    *
    * Compute mend inline to avoid a possible non-constant integer
    * multiply.
@@ -911,6 +919,23 @@ bool stm32_dmacapable(uint32_t maddr, uint32_t count, uint32_t ccr)
       return false;
     }
 
+#  if defined(CONFIG_ARMV7M_DCACHE) && !defined(CONFIG_ARMV7M_DCACHE_WRITETHROUGH)
+  /* buffer alignment is required for DMA transfers with dcache in buffered
+   * mode (not write-through) because a) arch_invalidate_dcache could lose
+   * buffered writes and b) arch_flush_dcache could corrupt adjacent memory if
+   * the maddr and the mend+1, the next next address are not on
+   * ARMV7M_DCACHE_LINESIZE boundaries.
+   */
+
+  if ((maddr & (ARMV7M_DCACHE_LINESIZE-1)) != 0 ||
+      ((mend + 1) & (ARMV7M_DCACHE_LINESIZE-1)) != 0)
+    {
+      dmainfo("stm32_dmacapable: dcache unaligned maddr:0x%08x mend:0x%08x\n",
+              maddr, mend);
+      return false;
+    }
+#  endif
+
   /* Verify that burst transfers do not cross a 1KiB boundary. */
 
   if ((maddr / 1024) != (mend / 1024))
diff --git NuttX/nuttx/arch/arm/src/stm32f7/stm32_dma.h NuttX/nuttx/arch/arm/src/stm32f7/stm32_dma.h
index b25cb84..e512b39 100644
--- NuttX/nuttx/arch/arm/src/stm32f7/stm32_dma.h
+++ NuttX/nuttx/arch/arm/src/stm32f7/stm32_dma.h
@@ -241,6 +241,13 @@ size_t stm32_dmaresidual(DMA_HANDLE handle);
  *   only applies to memory addresses, it will return false for any peripheral
  *   address.
  *
+ * Input Parameters:
+ *
+ *   maddr - starting memory address
+ *   count - number of unit8 or uint16 or uint32 items as defined by MSIZE of
+ *           ccr.
+ *   ccr   - DMA stream configuration register
+ *
  * Returned value:
  *   True, if transfer is possible.
  *
diff --git NuttX/nuttx/arch/arm/src/stm32f7/stm32_sdmmc.c NuttX/nuttx/arch/arm/src/stm32f7/stm32_sdmmc.c
index 2df98c1..7f81c97 100644
--- NuttX/nuttx/arch/arm/src/stm32f7/stm32_sdmmc.c
+++ NuttX/nuttx/arch/arm/src/stm32f7/stm32_sdmmc.c
@@ -2848,13 +2848,6 @@ static int stm32_dmapreflight(FAR struct sdio_dev_s *dev,
 
   DEBUGASSERT(priv != NULL && buffer != NULL && buflen > 0);
 
-  /* Wide bus operation is required for DMA */
-
-  if (!priv->widebus)
-    {
-      return -EINVAL;
-    }
-
   /* DMA must be possible to the buffer */
 
   if (!stm32_dmacapable((uintptr_t)buffer, (buflen + 3) >> 2,
@@ -2896,16 +2889,21 @@ static int stm32_dmarecvsetup(FAR struct sdio_dev_s *dev, FAR uint8_t *buffer,
   DEBUGASSERT(priv != NULL && buffer != NULL && buflen > 0);
 #ifdef CONFIG_SDIO_PREFLIGHT
   DEBUGASSERT(stm32_dmapreflight(dev, buffer, buflen) == 0);
-#endif
-
-#ifdef CONFIG_ARMV7M_DCACHE
-  /* buffer alignment is required for DMA transfers with dcache */
+#else
+#  if defined(CONFIG_ARMV7M_DCACHE) && !defined(CONFIG_ARMV7M_DCACHE_WRITETHROUGH)
+  /* buffer alignment is required for DMA transfers with dcache in buffered
+   * mode (not write-through) because the arch_invalidate_dcache could lose
+   * buffered buffered writes if the buffer alignment and sizes are not on
+   * ARMV7M_DCACHE_LINESIZE boundaries.
+   */
 
   if (((uintptr_t)buffer & (ARMV7M_DCACHE_LINESIZE-1)) != 0 ||
       (buflen & (ARMV7M_DCACHE_LINESIZE-1)) != 0)
     {
       return -EFAULT;
     }
+#  endif
+
 #endif
 
   /* Reset the DPSM configuration */
@@ -2981,16 +2979,20 @@ static int stm32_dmasendsetup(FAR struct sdio_dev_s *dev,
   DEBUGASSERT(priv != NULL && buffer != NULL && buflen > 0);
 #ifdef CONFIG_SDIO_PREFLIGHT
   DEBUGASSERT(stm32_dmapreflight(dev, buffer, buflen) == 0);
-#endif
-
-#ifdef CONFIG_ARMV7M_DCACHE
-  /* buffer alignment is required for DMA transfers with dcache */
+#else
+#  if defined(CONFIG_ARMV7M_DCACHE) && !defined(CONFIG_ARMV7M_DCACHE_WRITETHROUGH)
+  /* buffer alignment is required for DMA transfers with dcache in buffered
+   * mode (not write-through) because the arch_flush_dcache would corrupt adjacent
+   * memory if the buffer alignment and sizes are not on ARMV7M_DCACHE_LINESIZE
+   * boundaries.
+   */
 
   if (((uintptr_t)buffer & (ARMV7M_DCACHE_LINESIZE-1)) != 0 ||
       (buflen & (ARMV7M_DCACHE_LINESIZE-1)) != 0)
     {
       return -EFAULT;
     }
+#  endif
 #endif
 
   /* Reset the DPSM configuration */