From: Sascha Hauer <s.hauer@pengutronix.de>
To: barebox@lists.infradead.org
Subject: [PATCH 2/2] mtd core: call driver write function with complete buffer
Date: Thu, 29 Nov 2012 20:03:06 +0100 [thread overview]
Message-ID: <1354215786-25615-2-git-send-email-s.hauer@pengutronix.de> (raw)
In-Reply-To: <1354215786-25615-1-git-send-email-s.hauer@pengutronix.de>
mtd->write is supposed to loop around pages internally, no need
to do this in mtd_write. This fixes a huge write performance drop
with the m25p80 driver when it was converted to a mtd driver recently.
Since mtd->writesize is 1 for this driver mtd_write ended up doing
single byte writes on the flash.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
drivers/mtd/core.c | 56 +++-------------------------------------------------
1 file changed, 3 insertions(+), 53 deletions(-)
diff --git a/drivers/mtd/core.c b/drivers/mtd/core.c
index 8601787..b5916da 100644
--- a/drivers/mtd/core.c
+++ b/drivers/mtd/core.c
@@ -62,65 +62,15 @@ static ssize_t mtd_read(struct cdev *cdev, void* buf, size_t count,
#define MTDPGALG(x) ((x) & ~(mtd->writesize - 1))
#ifdef CONFIG_MTD_WRITE
-static int all_ff(const void *buf, int len)
-{
- int i;
- const uint8_t *p = buf;
-
- for (i = 0; i < len; i++)
- if (p[i] != 0xFF)
- return 0;
- return 1;
-}
-
static ssize_t mtd_write(struct cdev* cdev, const void *buf, size_t _count,
loff_t _offset, ulong flags)
{
struct mtd_info *mtd = cdev->priv;
- size_t retlen, now;
- int ret = 0;
- void *wrbuf = NULL;
- size_t count = _count;
- unsigned long offset = _offset;
-
- if (NOTALIGNED(offset)) {
- printf("offset 0x%0lx not page aligned\n", offset);
- return -EINVAL;
- }
-
- dev_dbg(cdev->dev, "write: offset: 0x%08lx count: 0x%zx\n", offset, count);
- while (count) {
- now = count > mtd->writesize ? mtd->writesize : count;
-
- if (NOTALIGNED(now)) {
- dev_dbg(cdev->dev, "not aligned: %d %ld\n",
- mtd->writesize,
- (offset % mtd->writesize));
- wrbuf = xmalloc(mtd->writesize);
- memset(wrbuf, 0xff, mtd->writesize);
- memcpy(wrbuf + (offset % mtd->writesize), buf, now);
- if (!all_ff(wrbuf, mtd->writesize))
- ret = mtd->write(mtd, MTDPGALG(offset),
- mtd->writesize, &retlen,
- wrbuf);
- free(wrbuf);
- } else {
- if (!all_ff(buf, mtd->writesize))
- ret = mtd->write(mtd, offset, now, &retlen,
- buf);
- dev_dbg(cdev->dev,
- "offset: 0x%08lx now: 0x%zx retlen: 0x%zx\n",
- offset, now, retlen);
- }
- if (ret)
- goto out;
+ size_t retlen;
+ int ret;
- offset += now;
- count -= now;
- buf += now;
- }
+ ret = mtd->write(mtd, _offset, _count, &retlen, buf);
-out:
return ret ? ret : _count;
}
#endif
--
1.7.10.4
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next prev parent reply other threads:[~2012-11-29 19:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-29 19:03 [PATCH 1/2] mtd oob: do not register oob device for devices without oob Sascha Hauer
2012-11-29 19:03 ` Sascha Hauer [this message]
2012-12-03 19:10 ` [PATCH 2/2] mtd core: call driver write function with complete buffer Robert Jarzmik
2012-12-05 16:53 ` Jean-Christophe PLAGNIOL-VILLARD
2012-12-05 17:15 ` [PATCH 1/1] mtd: nand: fix unaligned write support Jean-Christophe PLAGNIOL-VILLARD
2012-12-05 18:28 ` Sascha Hauer
2012-12-07 13:17 ` Jean-Christophe PLAGNIOL-VILLARD
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