part: efi: Add debugging for the signature check

Add a little more debugging for the initial signature check. Drop the
pointless check for NULL. Also set a log category while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/disk/part_efi.c b/disk/part_efi.c
index 20867521382247326e273ce725b60b9827683ac4..39382c5faee0876c97bd59359d00728e143c2e3a 100644 (file)
--- a/disk/part_efi.c
+++ b/disk/part_efi.c
@@ -9,6 +9,9 @@
  *   when CONFIG_SYS_64BIT_LBA is not defined, lbaint_t is 32 bits; this
  *   limits the maximum size of addressable storage to < 2 tebibytes
  */
+
+#define LOG_CATEGORY LOGC_FS
+
 #include <common.h>
 #include <blk.h>
 #include <log.h>
@@ -976,17 +979,23 @@ static int pmbr_part_valid(struct partition *part)
 /*
  * is_pmbr_valid(): test Protective MBR for validity
  *
+ * @mbr: Pointer to Master Boot-Record data
+ *
  * Returns: 1 if PMBR is valid, 0 otherwise.
  * Validity depends on two things:
  *  1) MSDOS signature is in the last two bytes of the MBR
  *  2) One partition of type 0xEE is found, checked by pmbr_part_valid()
  */
-static int is_pmbr_valid(legacy_mbr * mbr)
+static int is_pmbr_valid(legacy_mbr *mbr)
 {
+       uint sig = le16_to_cpu(mbr->signature);
        int i = 0;
 
-       if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
+       if (sig != MSDOS_MBR_SIGNATURE) {
+               log_debug("Invalid signature %x\n", sig);
                return 0;
+       }
+       log_debug("Signature %x valid\n", sig);
 
        for (i = 0; i < 4; i++) {
                if (pmbr_part_valid(&mbr->partition_record[i])) {