From 87ec3b7fa9061f470616ed927fc140e995831c00 Mon Sep 17 00:00:00 2001
From: Vladimir Serbinenko <phcoder@gmail.com>
Date: Fri, 27 Feb 2015 14:26:00 +0100
Subject: [PATCH] Don't continue to query block-size if disk doesn't have it.

Stops poluting screen with a lot of "block-size: exception -21".
---
 grub-core/disk/ieee1275/ofdisk.c | 62 ++++++++++++++++++++++----------
 include/grub/ieee1275/ofdisk.h   |  3 --
 2 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/grub-core/disk/ieee1275/ofdisk.c b/grub-core/disk/ieee1275/ofdisk.c
index 5d8863782..331769b12 100644
--- a/grub-core/disk/ieee1275/ofdisk.c
+++ b/grub-core/disk/ieee1275/ofdisk.c
@@ -35,6 +35,7 @@ struct ofdisk_hash_ent
   char *grub_devpath;
   int is_boot;
   int is_removable;
+  int block_size_fails;
   /* Pointer to shortest available name on nodes representing canonical names,
      otherwise NULL.  */
   const char *shortest;
@@ -42,6 +43,10 @@ struct ofdisk_hash_ent
   struct ofdisk_hash_ent *next;
 };
 
+static grub_err_t
+grub_ofdisk_get_block_size (const char *device, grub_uint32_t *block_size,
+			    struct ofdisk_hash_ent *op);
+
 #define OFDISK_HASH_SZ	8
 static struct ofdisk_hash_ent *ofdisk_hash[OFDISK_HASH_SZ];
 
@@ -375,6 +380,8 @@ grub_ofdisk_open (const char *name, grub_disk_t disk)
   /* XXX: This should be large enough for any possible case.  */
   char prop[64];
   grub_ssize_t actual;
+  grub_uint32_t block_size = 0;
+  grub_err_t err;
 
   if (grub_strncmp (name, "ieee1275/", sizeof ("ieee1275/") - 1) != 0)
       return grub_error (GRUB_ERR_UNKNOWN_DEVICE,
@@ -405,14 +412,6 @@ grub_ofdisk_open (const char *name, grub_disk_t disk)
       return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "not a block device");
     }
 
-  grub_uint32_t block_size = 0;
-  if (grub_ofdisk_get_block_size (devpath, &block_size) == 0)
-    {
-      for (disk->log_sector_size = 0;
-           (1U << disk->log_sector_size) < block_size;
-           disk->log_sector_size++);
-    }
-
   /* XXX: There is no property to read the number of blocks.  There
      should be a property `#blocks', but it is not there.  Perhaps it
      is possible to use seek for this.  */
@@ -429,6 +428,18 @@ grub_ofdisk_open (const char *name, grub_disk_t disk)
       return grub_errno;
     disk->id = (unsigned long) op;
     disk->data = op->open_path;
+
+    err = grub_ofdisk_get_block_size (devpath, &block_size, op);
+    if (err)
+      return err;
+    if (block_size != 0)
+      {
+	for (disk->log_sector_size = 0;
+	     (1U << disk->log_sector_size) < block_size;
+	     disk->log_sector_size++);
+      }
+    else
+      disk->log_sector_size = 9;
   }
 
   return 0;
@@ -589,8 +600,9 @@ grub_ofdisk_init (void)
   grub_disk_dev_register (&grub_ofdisk_dev);
 }
 
-grub_err_t
-grub_ofdisk_get_block_size (const char *device, grub_uint32_t *block_size)
+static grub_err_t
+grub_ofdisk_get_block_size (const char *device, grub_uint32_t *block_size,
+			    struct ofdisk_hash_ent *op)
 {
   struct size_args_ieee1275
     {
@@ -612,20 +624,34 @@ grub_ofdisk_get_block_size (const char *device, grub_uint32_t *block_size)
   if (! last_ihandle)
     return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "can't open device");
 
+  *block_size = 0;
+
+  if (op->block_size_fails >= 2)
+    return GRUB_ERR_NONE;
+
   INIT_IEEE1275_COMMON (&args_ieee1275.common, "call-method", 2, 2);
   args_ieee1275.method = (grub_ieee1275_cell_t) "block-size";
   args_ieee1275.ihandle = last_ihandle;
   args_ieee1275.result = 1;
 
-  *block_size = GRUB_DISK_SECTOR_SIZE;
-
-  if ((IEEE1275_CALL_ENTRY_FN (&args_ieee1275) == -1) || (args_ieee1275.result))
-    grub_dprintf ("disk", "can't get block size\n");
-  else
-    if (args_ieee1275.size1
-        && !(args_ieee1275.size1 & (args_ieee1275.size1 - 1))
-        && args_ieee1275.size1 >= 512 && args_ieee1275.size1 <= 16384)
+  if (IEEE1275_CALL_ENTRY_FN (&args_ieee1275) == -1)
+    {
+      grub_dprintf ("disk", "can't get block size: failed call-method\n");
+      op->block_size_fails++;
+    }
+  else if (args_ieee1275.result)
+    {
+      grub_dprintf ("disk", "can't get block size: %lld\n",
+		    (long long) args_ieee1275.result);
+      op->block_size_fails++;
+    }
+  else if (args_ieee1275.size1
+	   && !(args_ieee1275.size1 & (args_ieee1275.size1 - 1))
+	   && args_ieee1275.size1 >= 512 && args_ieee1275.size1 <= 16384)
+    {
+      op->block_size_fails = 0;
       *block_size = args_ieee1275.size1;
+    }
 
   return 0;
 }
diff --git a/include/grub/ieee1275/ofdisk.h b/include/grub/ieee1275/ofdisk.h
index 3f5831787..2f69e3f19 100644
--- a/include/grub/ieee1275/ofdisk.h
+++ b/include/grub/ieee1275/ofdisk.h
@@ -22,7 +22,4 @@
 extern void grub_ofdisk_init (void);
 extern void grub_ofdisk_fini (void);
 
-extern grub_err_t grub_ofdisk_get_block_size (const char *device,
-                                              grub_uint32_t *block_size);
-
 #endif /* ! GRUB_INIT_HEADER */