kernel/mediatek: 6.12: allow setting OF node for MSDOS partitions

Add patch to allow referencing MSDOS/MBR partitions in device tree to
allow legacy MT7623 boards to continue working with fitblk.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

diff --git a/target/linux/mediatek/patches-6.12/920-block-partitions-msdos-add-OF-node-by-partition-numb.patch b/target/linux/mediatek/patches-6.12/920-block-partitions-msdos-add-OF-node-by-partition-numb.patch
new file mode 100644 (file)
index 0000000..f2c3aa4
--- /dev/null
+++ b/target/linux/mediatek/patches-6.12/920-block-partitions-msdos-add-OF-node-by-partition-numb.patch
@@ -0,0 +1,98 @@
+From 391630263f08dc853b111c6c3325a0ec510fe5fb Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Fri, 9 May 2025 02:38:51 +0100
+Subject: [PATCH] block: partitions: msdos: add OF node by partition number
+
+A hack for some legacy boards...
+
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+---
+ block/partitions/msdos.c | 66 +++++++++++++++++++++++++++++++++-------
+ 1 file changed, 55 insertions(+), 11 deletions(-)
+
+--- a/block/partitions/msdos.c
++++ b/block/partitions/msdos.c
+@@ -27,6 +27,7 @@
+  */
+ #include <linux/msdos_fs.h>
+ #include <linux/msdos_partition.h>
++#include <linux/of.h>
+ 
+ #include "check.h"
+ #include "efi.h"
+@@ -116,6 +117,26 @@ static void set_info(struct parsed_parti
+       state->parts[slot].has_info = true;
+ }
+ 
++static struct device_node *find_partno_of_node(struct device_node *partitions_np,
++                                                int partno)
++{
++      int np_partno;
++
++      if (!partitions_np ||
++          !of_device_is_compatible(partitions_np, "msdos-partitions"))
++              return NULL;
++
++      for_each_available_child_of_node_scoped(partitions_np, np) {
++              if (!of_property_read_u32(np, "partno", &np_partno) &&
++                  partno != np_partno)
++                      continue;
++
++              return np;
++      }
++
++      return NULL;
++}
++
+ /*
+  * Create devices for each logical partition in an extended partition.
+  * The logical partitions form a linked list, with each entry being
+@@ -131,6 +152,8 @@ static void parse_extended(struct parsed
+                          sector_t first_sector, sector_t first_size,
+                          u32 disksig)
+ {
++      struct device *ddev = disk_to_dev(state->disk);
++      struct device_node *partitions_np = of_node_get(ddev->of_node);
+       struct msdos_partition *p;
+       Sector sect;
+       unsigned char *data;
+@@ -190,7 +213,8 @@ static void parse_extended(struct parsed
+                                       continue;
+                       }
+ 
+-                      put_partition(state, state->next, next, size);
++                      of_put_partition(state, state->next, next, size,
++                                       find_partno_of_node(partitions_np, state->next));
+                       set_info(state, state->next, disksig);
+                       if (p->sys_ind == LINUX_RAID_PARTITION)
+                               state->parts[state->next].flags = ADDPART_FLAG_RAID;
+@@ -580,6 +604,8 @@ static struct {
+ 
+ int msdos_partition(struct parsed_partitions *state)
+ {
++      struct device *ddev = disk_to_dev(state->disk);
++      struct device_node *partitions_np = of_node_get(ddev->of_node);
+       sector_t sector_size;
+       Sector sect;
+       unsigned char *data;
+@@ -676,14 +702,18 @@ int msdos_partition(struct parsed_partit
+                       sector_t n = 2;
+ 
+                       n = min(size, max(sector_size, n));
+-                      put_partition(state, slot, start, n);
++                      of_put_partition(state, slot, start, n,
++                                       find_partno_of_node(partitions_np,
++                                                           slot));
+ 
+                       strlcat(state->pp_buf, " <", PAGE_SIZE);
+                       parse_extended(state, start, size, disksig);
+                       strlcat(state->pp_buf, " >", PAGE_SIZE);
+                       continue;
+               }
+-              put_partition(state, slot, start, size);
++              of_put_partition(state, slot, start, size,
++                               find_partno_of_node(partitions_np,
++                                                   slot));
+               set_info(state, slot, disksig);
+               if (p->sys_ind == LINUX_RAID_PARTITION)
+                       state->parts[slot].flags = ADDPART_FLAG_RAID;