firewire: core: code refactoring to detect both IEEE 1394:1995 IRM and Canon MV5i

The detection of IEEE 1394:1995 and Canon MV5i is just required within
some of the condition branches. In this case, these check can be
capsulated within these branches.

This commit refactors the checks.

Link: https://lore.kernel.org/r/20250908012108.514698-10-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 630e229..99aa98f 100644 (file)
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -289,15 +289,13 @@ static void bm_work(struct work_struct *work)
                63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
        };
        struct fw_card *card __free(card_unref) = from_work(card, work, bm_work.work);
-       struct fw_device *root_device, *irm_device;
+       struct fw_device *root_device;
        struct fw_node *root_node __free(node_unref) = NULL;
        int root_id, new_root_id, irm_id, local_id;
        int expected_gap_count, generation, grace;
        bool do_reset = false;
        bool root_device_is_running;
        bool root_device_is_cmc;
-       bool irm_is_1394_1995_only;
-       bool keep_this_irm;
 
        lockdep_assert_held(&card->lock);
 
@@ -316,14 +314,6 @@ static void bm_work(struct work_struct *work)
                        atomic_read(&root_device->state) == FW_DEVICE_RUNNING;
        root_device_is_cmc = root_device && root_device->cmc;
 
-       irm_device = fw_node_get_device(card->irm_node);
-       irm_is_1394_1995_only = irm_device && irm_device->config_rom &&
-                       (irm_device->config_rom[2] & 0x000000f0) == 0;
-
-       /* Canon MV5i works unreliably if it is not root node. */
-       keep_this_irm = irm_device && irm_device->config_rom &&
-                       irm_device->config_rom[3] >> 8 == CANON_OUI;
-
        root_id  = root_node->node_id;
        irm_id   = card->irm_node->node_id;
        local_id = card->local_node->node_id;
@@ -349,6 +339,9 @@ static void bm_work(struct work_struct *work)
                        cpu_to_be32(0x3f),
                        cpu_to_be32(local_id),
                };
+               struct fw_device *irm_device = fw_node_get_device(card->irm_node);
+               bool irm_is_1394_1995_only = false;
+               bool keep_this_irm = false;
                int rcode;
 
                if (!card->irm_node->link_on) {
@@ -358,6 +351,13 @@ static void bm_work(struct work_struct *work)
                        goto pick_me;
                }
 
+               if (irm_device && irm_device->config_rom) {
+                       irm_is_1394_1995_only = (irm_device->config_rom[2] & 0x000000f0) == 0;
+
+                       // Canon MV5i works unreliably if it is not root node.
+                       keep_this_irm = irm_device->config_rom[3] >> 8 == CANON_OUI;
+               }
+
                if (irm_is_1394_1995_only && !keep_this_irm) {
                        new_root_id = local_id;
                        fw_notice(card, "%s, making local node (%02x) root\n",