arm: socfpga: mailbox: Fix off-by-one error on command length checking
A mailbox command contains 1-u32 header + arguments. The "len" variable
only contains the length of the arguments, but not the 1-u32 header.
Include the length of header when checking the ring buffer space to
prevent off-by-one error.
Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com>
diff --git a/arch/arm/mach-socfpga/mailbox_s10.c b/arch/arm/mach-socfpga/mailbox_s10.c
index 3c33223..4498ab5 100644
--- a/arch/arm/mach-socfpga/mailbox_s10.c
+++ b/arch/arm/mach-socfpga/mailbox_s10.c
@@ -55,11 +55,11 @@
cout = MBOX_READL(MBOX_COUT) % MBOX_CMD_BUFFER_SIZE;
/* if command buffer is full or not enough free space
- * to fit the data
+ * to fit the data. Note, len is in u32 unit.
*/
if (((cin + 1) % MBOX_CMD_BUFFER_SIZE) == cout ||
((MBOX_CMD_BUFFER_SIZE - cin + cout - 1) %
- MBOX_CMD_BUFFER_SIZE) < len)
+ MBOX_CMD_BUFFER_SIZE) < (len + 1))
return -ENOMEM;
/* write header to circular buffer */