From 1e566bc6dbcfc9f13909d5cb40dd74925bcdd579 Mon Sep 17 00:00:00 2001
From: Simon Glass <sjg@chromium.org>
Date: Mon, 11 Mar 2013 06:08:06 +0000
Subject: [PATCH] sf: Respect maximum SPI write size

Some SPI flash controllers (e.g. Intel ICH) have a limit on the number of
bytes that can be in a write transaction. Support this by breaking the
writes into multiple transactions.

Signed-off-by: Simon Glass <sjg@chromium.org>
---
 drivers/mtd/spi/spi_flash.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index 17f3d3cb147..b82011d0fd2 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -87,6 +87,9 @@ int spi_flash_cmd_write_multi(struct spi_flash *flash, u32 offset,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		chunk_len = min(len - actual, page_size - byte_addr);
 
+		if (flash->spi->max_write_size)
+			chunk_len = min(chunk_len, flash->spi->max_write_size);
+
 		cmd[1] = page_addr >> 8;
 		cmd[2] = page_addr;
 		cmd[3] = byte_addr;
@@ -111,8 +114,11 @@ int spi_flash_cmd_write_multi(struct spi_flash *flash, u32 offset,
 		if (ret)
 			break;
 
-		page_addr++;
-		byte_addr = 0;
+		byte_addr += chunk_len;
+		if (byte_addr == page_size) {
+			page_addr++;
+			byte_addr = 0;
+		}
 	}
 
 	debug("SF: program %s %zu bytes @ %#x\n",
-- 
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