flash debugging

patches/openwrt/0009-add-patch-for-flash-debugging.patch

+From: Nico <github@nicoboehr.de>
+Date: Sun, 9 Mar 2025 11:05:38 +0000
+Subject: add patch for flash debugging
+
+diff --git a/target/linux/ath79/patches-6.6/910-flashdebug.patch b/target/linux/ath79/patches-6.6/910-flashdebug.patch
+new file mode 100644
+index 0000000000000000000000000000000000000000..239cc92b973a8989ac65aa8ebd7447823b01ee6a
+--- /dev/null
++++ b/target/linux/ath79/patches-6.6/910-flashdebug.patch
+@@ -0,0 +1,141 @@
++--- a/drivers/mtd/mtdcore.c
+++++ b/drivers/mtd/mtdcore.c
++@@ -6,6 +6,7 @@
++  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
++  * Copyright © 2006      Red Hat UK Limited 
++  */
+++#define DEBUG
++ 
++ #include <linux/module.h>
++ #include <linux/kernel.h>
++@@ -2299,20 +2300,29 @@ EXPORT_SYMBOL_GPL(mtd_lock);
++ int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
++ {
++ 	struct mtd_info *master = mtd_get_master(mtd);
+++	int r;
++ 
++-	if (!master->_unlock)
+++	if (!master->_unlock) {
+++		printk("mtd: no unlock operation for %s\n", mtd->name);
++ 		return -EOPNOTSUPP;
++-	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
+++	}
+++	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) {
+++		printk("mtd: unlock out of band for %s\n", mtd->name);
++ 		return -EINVAL;
++-	if (!len)
+++	}
+++	if (!len) {
+++		printk("mtd: zero length %s\n", mtd->name);
++ 		return 0;
+++	}
++ 
++ 	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
++ 		ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
++ 		len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
++ 	}
++ 
++-	return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
+++	r = master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
+++	printk("mtd_unlock: %s return %d\n", mtd->name, r);
+++	return r;
++ }
++ EXPORT_SYMBOL_GPL(mtd_unlock);
++ 
++--- a/drivers/mtd/spi-nor/core.c
+++++ b/drivers/mtd/spi-nor/core.c
++@@ -6,6 +6,7 @@
++  * Copyright (C) 2005, Intec Automation Inc.
++  * Copyright (C) 2014, Freescale Semiconductor, Inc.
++  */
+++#define DEBUG
++ 
++ #include <linux/err.h>
++ #include <linux/errno.h>
++--- a/fs/jffs2/build.c
+++++ b/fs/jffs2/build.c
++@@ -119,12 +119,12 @@ static int jffs2_build_filesystem(struct
++ 
++ 	if (c->flags & (1 << 7)) {
++ 		printk("%s(): unlocking the mtd device... ", __func__);
++-		mtd_unlock(c->mtd, 0, c->mtd->size);
++-		printk("done.\n");
+++		ret = mtd_unlock(c->mtd, 0, c->mtd->size);
+++		printk("unlock done with ret=%d.\n", ret);
++ 
++ 		printk("%s(): erasing all blocks after the end marker... ", __func__);
++-		jffs2_erase_pending_blocks(c, -1);
++-		printk("done.\n");
+++		ret = jffs2_erase_pending_blocks(c, -1);
+++		printk("erase done with ret=%d.\n", ret);
++ 	}
++ 
++ 	dbg_fsbuild("pass 1 starting\n");
++--- a/drivers/mtd/spi-nor/swp.c
+++++ b/drivers/mtd/spi-nor/swp.c
++@@ -253,15 +253,21 @@ static int spi_nor_sr_unlock(struct spi_
++ 	bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;
++ 	bool use_top;
++ 
+++	printk("nor->flags = %x\n", nor->flags);
+++
++ 	ret = spi_nor_read_sr(nor, nor->bouncebuf);
++-	if (ret)
+++	if (ret) {
+++		printk("spi_nor_sr_unlock: spi_no_read_sr() failed with %d\n", ret);
++ 		return ret;
+++	}
++ 
++ 	status_old = nor->bouncebuf[0];
++ 
++ 	/* If nothing in our range is locked, we don't need to do anything */
++-	if (spi_nor_is_unlocked_sr(nor, ofs, len, status_old))
+++	if (spi_nor_is_unlocked_sr(nor, ofs, len, status_old)) {
+++		printk("spi_nor_sr_unlock: already unlocked");
++ 		return 0;
+++	}
++ 
++ 	/* If anything below us is locked, we can't use 'top' protection */
++ 	if (!spi_nor_is_unlocked_sr(nor, 0, ofs, status_old))
++@@ -272,8 +278,10 @@ static int spi_nor_sr_unlock(struct spi_
++ 				    status_old))
++ 		can_be_bottom = false;
++ 
++-	if (!can_be_bottom && !can_be_top)
+++	if (!can_be_bottom && !can_be_top) {
+++		printk("spi_nor_sr_unlock: ofs=%lld len=%llu mtd->size=%llu\n", ofs, len, mtd->size);
++ 		return -EINVAL;
+++	}
++ 
++ 	/* Prefer top, if both are valid */
++ 	use_top = can_be_top;
++@@ -295,8 +303,10 @@ static int spi_nor_sr_unlock(struct spi_
++ 			val = (val & ~SR_BP3) | SR_BP3_BIT6;
++ 
++ 		/* Some power-of-two sizes are not supported */
++-		if (val & ~mask)
+++		if (val & ~mask) {
+++			printk("spi_nor_sr_unlock: unsupported power of two: val=%x mask=%x\n", val, mask);
++ 			return -EINVAL;
+++		}
++ 	}
++ 
++ 	status_new = (status_old & ~mask & ~tb_mask) | val;
++@@ -313,10 +323,15 @@ static int spi_nor_sr_unlock(struct spi_
++ 		return 0;
++ 
++ 	/* Only modify protection if it will not lock other areas */
++-	if ((status_new & mask) > (status_old & mask))
+++	if ((status_new & mask) > (status_old & mask)) {
+++		printk("spi_nor_sr_unlock: status_new=%x status_old=%x\n", status_new, status_old);
++ 		return -EINVAL;
+++	}
++ 
++-	return spi_nor_write_sr_and_check(nor, status_new);
+++	ret = spi_nor_write_sr_and_check(nor, status_new);
+++	if (ret)
+++		printk("spi_nor_sr_unlock: spi_nor_write_sr_and_check failed with %d\n", ret);
+++	return ret;
++ }
++ 
++ /*