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MTD: atmel_nand: Fall back to CPU I/O when buffer is in vmalloc(ed) region

PATCH New Hong Xu 2 participants 2 messages Mar 31, 2011 – Apr 1, 2011

Subsystems (3)
Memory technology devices (MTD) Arm/Microchip (AT91) SoC support NAND flash
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Hong Xu

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PATCH 1/1 MTD: atmel_nand: Fall back to CPU I/O when buffer is in vmalloc(ed) region

The previous way of dealing with vmalloc(ed) region by walking though the pages can not work well actually. We just fall back to CPU I/O when the buffer address is higher than `high_memory'.

Signed-off-by Nicolas Ferre <[email protected]>
Signed-off-by Hong Xu <[email protected]>
---
 drivers/mtd/nand/atmel_nand.c |   18 ++----------------
 1 files changed, 2 insertions(+), 16 deletions(-)
drivers/mtd/nand/atmel_nand.c +2 -16
index 1b43654..ed0863a 100644
@@ -209,22 +209,8 @@ static int atmel_nand_dma_op(struct mtd_info *mtd, void *buf, int len,
 	int err = -EIO;
 	enum dma_data_direction dir = is_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 
-	if (buf >= high_memory) {
-		struct page *pg;
-
-		if (((size_t)buf & PAGE_MASK) !=
-		    ((size_t)(buf + len - 1) & PAGE_MASK)) {
-			dev_warn(host->dev, "Buffer not fit in one page\n");
-			goto err_buf;
-		}
-
-		pg = vmalloc_to_page(buf);
-		if (pg == 0) {
-			dev_err(host->dev, "Failed to vmalloc_to_page\n");
-			goto err_buf;
-		}
-		p = page_address(pg) + ((size_t)buf & ~PAGE_MASK);
-	}
+	if (buf >= high_memory)
+		goto err_buf;
 
 	dma_dev = host->dma_chan->device;
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1.7.3.3
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#1 lore raw

PATCH 1/1 MTD: atmel_nand: Fall back to CPU I/O when buffer is in vmalloc(ed) region

Quoted 5 lines · Hong Xu

The previous way of dealing with vmalloc(ed) region by walking though the pages can not work well actually. We just fall back to CPU I/O when the buffer address is higher than `high_memory'.

Signed-off-by Nicolas Ferre <[email protected]>
Signed-off-by Hong Xu <[email protected]>

Pushed to l2-mtd-2.6.git, thanks!

Signature · 2 lines
Best Regards,
Artem Bityutskiy (????? ????????)