OneNAND: Invalidate bufferRAM after erase

From: Adrian Hunter <[email protected]>
Date: Wed, 7 Feb 2007 13:55:19 +0200
Subject: [MTD] OneNAND: Invalidate bufferRAM after erase

OneNAND has internal bufferRAMs. The driver keeps track of what is in the bufferRAM to save having to load from the NAND core. After an erase operation, the driver must mark bufferRAM invalid if it refers to the erased block.

---
drivers/mtd/onenand/onenand_base.c | 25 +++++++++++++++++++++++++

1 files changed, 25 insertions(+), 0 deletions(-)

index f690c19..cf66c93 100644
@@ -628,6 +628,29 @@ static void onenand_update_bufferram(str

}

/**
+ * onenand_invalidate_bufferram_range - [GENERIC] Invalidate BufferRAM information
+ * @param mtd MTD data structure
+ * @param addr start address to invalidate
+ * @param len length to invalidate
+ *
+ * Invalidate BufferRAM information
+ */
+static void onenand_invalidate_bufferram_range(struct mtd_info *mtd, loff_t addr,
+ unsigned int len)
+{
+ struct onenand_chip *this = mtd->priv;
+ int i;
+ loff_t end_addr = addr + len;
+
+ /* Invalidate BufferRAM */
+ for (i = 0; i < MAX_BUFFERRAM; i++) {
+ loff_t buf_addr = this->bufferram[i].blockpage << this->page_shift;
+ if (buf_addr >= addr && buf_addr < end_addr)
+ this->bufferram[i].blockpage = -1;
+ }
+}
+
+/**
* onenand_get_device - [GENERIC] Get chip for selected access
* @param mtd MTD device structure
* @param new_state the state which is requested
@@ -1466,6 +1489,8 @@ static int onenand_erase(struct mtd_info

			goto erase_exit;
		}

+ onenand_invalidate_bufferram_range(mtd, addr, block_size);
+

		this->command(mtd, ONENAND_CMD_ERASE, addr, block_size);

		ret = this->wait(mtd, FL_ERASING);

1.4.3

Hi Adrian,

I checked it with pagetest module. Without the patch it failed. I have two minor comments.

Thank you,
Kyungmin Park

From: Adrian Hunter <[email protected]>
Date: Wed, 7 Feb 2007 13:55:19 +0200
Subject: [MTD] OneNAND: Invalidate bufferRAM after erase

OneNAND has internal bufferRAMs. The driver keeps track of what is in the bufferRAM to save having to load from the NAND core. After an erase operation, the driver must mark bufferRAM invalid if it refers to the erased block.

---
 drivers/mtd/onenand/onenand_base.c |   25 +++++++++++++++++++++++++
 1 files changed, 25 insertions(+), 0 deletions(-)

index f690c19..cf66c93 100644
@@ -628,6 +628,29 @@ static void onenand_update_bufferram(str
 }
 
 /**
+ * onenand_invalidate_bufferram - [GENERIC] Invalidate BufferRAM information
+ * @param mtd		MTD data structure
+ * @param addr		start address to invalidate
+ * @param len		length to invalidate
+ *
+ * Invalidate BufferRAM information
+ */
+static void onenand_invalidate_bufferram(struct mtd_info *mtd, loff_t addr,
+		unsigned int len)
+{
+	struct onenand_chip *this = mtd->priv;
+	int i;
+	loff_t end_addr = addr + len;
+
+	/* Invalidate BufferRAM */
+	for (i = 0; i < MAX_BUFFERRAM; i++) {
+		loff_t buf_addr = this->bufferram[i].blockpage << this->page_shift;
+		if (buf_addr >= addr && buf_addr < end_addr)
+			this->bufferram[i].blockpage = -1;
+	}
+}
+
+/**
  * onenand_get_device - [GENERIC] Get chip for selected access
  * @param mtd		MTD device structure
  * @param new_state	the state which is requested

@@ -1466,6 +1489,8 @@ static int onenand_erase(struct mtd_info
 
 		this->command(mtd, ONENAND_CMD_ERASE, addr, block_size);
 
+		onenand_invalidate_bufferram(mtd, addr, block_size);
+
 		ret = this->wait(mtd, FL_ERASING);
 		/* Check, if it is write protected */
 		if (ret) {

1.4.3

I've pulled from the onenand git tree and applied this extra patch.

dwmw2