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authorRussell King <rmk+kernel@arm.linux.org.uk>2014-04-25 12:59:00 +0100
committerChris Ball <chris@printf.net>2014-05-22 07:26:32 -0400
commit9d2fc80fb15b99736ecd1895934ce4512e76fa3f (patch)
treea4d3d16bb8b27dca5d06cd1f7cf136a00caf8132 /drivers/mmc
parent1771059cf5f9c09e37ef6315df8acf120f2642fc (diff)
downloadop-kernel-dev-9d2fc80fb15b99736ecd1895934ce4512e76fa3f.zip
op-kernel-dev-9d2fc80fb15b99736ecd1895934ce4512e76fa3f.tar.gz
mmc: sdhci-esdhc-imx: avoid DMA to kernel stack
sdhci-esdhc-imx tries to DMA to the kernel stack when tuning the interface, which causes dma-debug to complain. Fix this by kmallocing a buffer to hold the received tuning pattern. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Tested-by: Markus Pargmann <mpa@pengutronix.de> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Chris Ball <chris@printf.net>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci-esdhc-imx.c25
1 files changed, 16 insertions, 9 deletions
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index ce8939f..5acfe2f 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -711,13 +711,12 @@ static void esdhc_request_done(struct mmc_request *mrq)
complete(&mrq->completion);
}
-static int esdhc_send_tuning_cmd(struct sdhci_host *host, u32 opcode)
+static int esdhc_send_tuning_cmd(struct sdhci_host *host, u32 opcode,
+ struct scatterlist *sg)
{
struct mmc_command cmd = {0};
struct mmc_request mrq = {NULL};
struct mmc_data data = {0};
- struct scatterlist sg;
- char tuning_pattern[ESDHC_TUNING_BLOCK_PATTERN_LEN];
cmd.opcode = opcode;
cmd.arg = 0;
@@ -726,11 +725,9 @@ static int esdhc_send_tuning_cmd(struct sdhci_host *host, u32 opcode)
data.blksz = ESDHC_TUNING_BLOCK_PATTERN_LEN;
data.blocks = 1;
data.flags = MMC_DATA_READ;
- data.sg = &sg;
+ data.sg = sg;
data.sg_len = 1;
- sg_init_one(&sg, tuning_pattern, sizeof(tuning_pattern));
-
mrq.cmd = &cmd;
mrq.cmd->mrq = &mrq;
mrq.data = &data;
@@ -770,13 +767,21 @@ static void esdhc_post_tuning(struct sdhci_host *host)
static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode)
{
+ struct scatterlist sg;
+ char *tuning_pattern;
int min, max, avg, ret;
+ tuning_pattern = kmalloc(ESDHC_TUNING_BLOCK_PATTERN_LEN, GFP_KERNEL);
+ if (!tuning_pattern)
+ return -ENOMEM;
+
+ sg_init_one(&sg, tuning_pattern, ESDHC_TUNING_BLOCK_PATTERN_LEN);
+
/* find the mininum delay first which can pass tuning */
min = ESDHC_TUNE_CTRL_MIN;
while (min < ESDHC_TUNE_CTRL_MAX) {
esdhc_prepare_tuning(host, min);
- if (!esdhc_send_tuning_cmd(host, opcode))
+ if (!esdhc_send_tuning_cmd(host, opcode, &sg))
break;
min += ESDHC_TUNE_CTRL_STEP;
}
@@ -785,7 +790,7 @@ static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode)
max = min + ESDHC_TUNE_CTRL_STEP;
while (max < ESDHC_TUNE_CTRL_MAX) {
esdhc_prepare_tuning(host, max);
- if (esdhc_send_tuning_cmd(host, opcode)) {
+ if (esdhc_send_tuning_cmd(host, opcode, &sg)) {
max -= ESDHC_TUNE_CTRL_STEP;
break;
}
@@ -795,9 +800,11 @@ static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode)
/* use average delay to get the best timing */
avg = (min + max) / 2;
esdhc_prepare_tuning(host, avg);
- ret = esdhc_send_tuning_cmd(host, opcode);
+ ret = esdhc_send_tuning_cmd(host, opcode, &sg);
esdhc_post_tuning(host);
+ kfree(tuning_pattern);
+
dev_dbg(mmc_dev(host->mmc), "tunning %s at 0x%x ret %d\n",
ret ? "failed" : "passed", avg, ret);
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