[PATCH] mmc: msm: fix dma usage not to use internal APIs

Daniel Walker dwalker at codeaurora.org
Tue Jan 18 17:25:18 EST 2011


This doesn't work yet. I tried booting with this patch, and the boot
stops after detecting the MMC partitions. It won't actually boot off
the MMC. Without this patch and with the page_to_dma/pfn_to_dma changes
it does work.

Not-Signed-off-by: Daniel Walker <dwalker at codeaurora.org>
---
 drivers/mmc/host/msm_sdcc.c |   46 +++++++++++++++++-------------------------
 1 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/drivers/mmc/host/msm_sdcc.c b/drivers/mmc/host/msm_sdcc.c
index 5decfd0..1f1c7cb 100644
--- a/drivers/mmc/host/msm_sdcc.c
+++ b/drivers/mmc/host/msm_sdcc.c
@@ -383,14 +383,27 @@ static int msmsdcc_config_dma(struct msmsdcc_host *host, struct mmc_data *data)
 	host->curr.user_pages = 0;
 
 	box = &nc->cmd[0];
-	for (i = 0; i < host->dma.num_ents; i++) {
-		box->cmd = CMD_MODE_BOX;
 
-	/* Initialize sg dma address */
-	sg->dma_address = page_to_dma(mmc_dev(host->mmc), sg_page(sg))
-				+ sg->offset;
+	/* location of command block must be 64 bit aligned */
+	BUG_ON(host->dma.cmd_busaddr & 0x07);
 
-	if (i == (host->dma.num_ents - 1))
+	nc->cmdptr = (host->dma.cmd_busaddr >> 3) | CMD_PTR_LP;
+	host->dma.hdr.cmdptr = DMOV_CMD_PTR_LIST |
+			       DMOV_CMD_ADDR(host->dma.cmdptr_busaddr);
+	host->dma.hdr.complete_func = msmsdcc_dma_complete_func;
+
+	n = dma_map_sg(mmc_dev(host->mmc), host->dma.sg,
+			host->dma.num_ents, host->dma.dir);
+	if (n == 0) {
+		printk(KERN_ERR "%s: Unable to map in all sg elements\n",
+			mmc_hostname(host->mmc));
+		host->dma.sg = NULL;
+		host->dma.num_ents = 0;
+		return -ENOMEM;
+	}
+
+	for_each_sg(host->dma.sg, sg, n, i) {
+		if (i == n - 1)
 			box->cmd |= CMD_LC;
 		rows = (sg_dma_len(sg) % MCI_FIFOSIZE) ?
 			(sg_dma_len(sg) / MCI_FIFOSIZE) + 1 :
@@ -418,27 +431,6 @@ static int msmsdcc_config_dma(struct msmsdcc_host *host, struct mmc_data *data)
 			box->cmd |= CMD_DST_CRCI(crci);
 		}
 		box++;
-		sg++;
-	}
-
-	/* location of command block must be 64 bit aligned */
-	BUG_ON(host->dma.cmd_busaddr & 0x07);
-
-	nc->cmdptr = (host->dma.cmd_busaddr >> 3) | CMD_PTR_LP;
-	host->dma.hdr.cmdptr = DMOV_CMD_PTR_LIST |
-			       DMOV_CMD_ADDR(host->dma.cmdptr_busaddr);
-	host->dma.hdr.complete_func = msmsdcc_dma_complete_func;
-
-	n = dma_map_sg(mmc_dev(host->mmc), host->dma.sg,
-			host->dma.num_ents, host->dma.dir);
-/* dsb inside dma_map_sg will write nc out to mem as well */
-
-	if (n != host->dma.num_ents) {
-		printk(KERN_ERR "%s: Unable to map in all sg elements\n",
-			mmc_hostname(host->mmc));
-		host->dma.sg = NULL;
-		host->dma.num_ents = 0;
-		return -ENOMEM;
 	}
 
 	return 0;
-- 
1.7.0.4

-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.



More information about the linux-arm-kernel mailing list