mmc: cull sg list to match mmc request size
mmc layer may introduce additional (compared to block layer) limits on
request size. Culling of the sg list to match adjusted request size
simplifies the handling of such cases in the low level driver, allowing
it to skip block count checks while processing sg entries.
(fixes for wbsd and sdhci by Pierre Ossman)
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index d749f08..587dccf 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -1,7 +1,7 @@
/*
* linux/drivers/mmc/sdhci.c - Secure Digital Host Controller Interface driver
*
- * Copyright (C) 2005-2006 Pierre Ossman, All Rights Reserved.
+ * Copyright (C) 2005-2007 Pierre Ossman, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -247,14 +247,13 @@
chunk_remain = min(blksize, 4);
}
- size = min(host->size, host->remain);
- size = min(size, chunk_remain);
+ size = min(host->remain, chunk_remain);
chunk_remain -= size;
blksize -= size;
host->offset += size;
host->remain -= size;
- host->size -= size;
+
while (size) {
*buffer = data & 0xFF;
buffer++;
@@ -289,14 +288,13 @@
buffer = sdhci_sg_to_buffer(host) + host->offset;
while (blksize) {
- size = min(host->size, host->remain);
- size = min(size, chunk_remain);
+ size = min(host->remain, chunk_remain);
chunk_remain -= size;
blksize -= size;
host->offset += size;
host->remain -= size;
- host->size -= size;
+
while (size) {
data >>= 8;
data |= (u32)*buffer << 24;
@@ -325,7 +323,7 @@
BUG_ON(!host->data);
- if (host->size == 0)
+ if (host->num_sg == 0)
return;
if (host->data->flags & MMC_DATA_READ)
@@ -339,10 +337,8 @@
else
sdhci_write_block_pio(host);
- if (host->size == 0)
+ if (host->num_sg == 0)
break;
-
- BUG_ON(host->num_sg == 0);
}
DBG("PIO transfer complete.\n");
@@ -408,8 +404,6 @@
writel(sg_dma_address(data->sg), host->ioaddr + SDHCI_DMA_ADDRESS);
} else {
- host->size = data->blksz * data->blocks;
-
host->cur_sg = data->sg;
host->num_sg = data->sg_len;
@@ -473,10 +467,6 @@
"though there were blocks left.\n",
mmc_hostname(host->mmc));
data->error = MMC_ERR_FAILED;
- } else if (host->size != 0) {
- printk(KERN_ERR "%s: %d bytes were left untransferred.\n",
- mmc_hostname(host->mmc), host->size);
- data->error = MMC_ERR_FAILED;
}
DBG("Ending data transfer (%d bytes)\n", data->bytes_xfered);