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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>
This commit is contained in:
Russell King 2014-04-25 12:59:00 +01:00 committed by Chris Ball
parent 1771059cf5
commit 9d2fc80fb1
1 changed files with 16 additions and 9 deletions
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25
drivers/mmc/host/sdhci-esdhc-imx.c
View File

@ -711,13 +711,12 @@ static void esdhc_request_done(struct mmc_request *mrq)
complete(&mrq->completion); 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_command cmd = {0};
struct mmc_request mrq = {NULL}; struct mmc_request mrq = {NULL};
struct mmc_data data = {0}; struct mmc_data data = {0};
struct scatterlist sg;
char tuning_pattern[ESDHC_TUNING_BLOCK_PATTERN_LEN];
cmd.opcode = opcode; cmd.opcode = opcode;
cmd.arg = 0; 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.blksz = ESDHC_TUNING_BLOCK_PATTERN_LEN;
data.blocks = 1; data.blocks = 1;
data.flags = MMC_DATA_READ; data.flags = MMC_DATA_READ;
data.sg = &sg; data.sg = sg;
data.sg_len = 1; data.sg_len = 1;
sg_init_one(&sg, tuning_pattern, sizeof(tuning_pattern));
mrq.cmd = &cmd; mrq.cmd = &cmd;
mrq.cmd->mrq = &mrq; mrq.cmd->mrq = &mrq;
mrq.data = &data; 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) static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode)
{ {
struct scatterlist sg;
char *tuning_pattern;
int min, max, avg, ret; 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 */ /* find the mininum delay first which can pass tuning */
min = ESDHC_TUNE_CTRL_MIN; min = ESDHC_TUNE_CTRL_MIN;
while (min < ESDHC_TUNE_CTRL_MAX) { while (min < ESDHC_TUNE_CTRL_MAX) {
esdhc_prepare_tuning(host, min); esdhc_prepare_tuning(host, min);
if (!esdhc_send_tuning_cmd(host, opcode)) if (!esdhc_send_tuning_cmd(host, opcode, &sg))
break; break;
min += ESDHC_TUNE_CTRL_STEP; 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; max = min + ESDHC_TUNE_CTRL_STEP;
while (max < ESDHC_TUNE_CTRL_MAX) { while (max < ESDHC_TUNE_CTRL_MAX) {
esdhc_prepare_tuning(host, 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; max -= ESDHC_TUNE_CTRL_STEP;
break; break;
} }
@ -795,9 +800,11 @@ static int esdhc_executing_tuning(struct sdhci_host *host, u32 opcode)
/* use average delay to get the best timing */ /* use average delay to get the best timing */
avg = (min + max) / 2; avg = (min + max) / 2;
esdhc_prepare_tuning(host, avg); esdhc_prepare_tuning(host, avg);
ret = esdhc_send_tuning_cmd(host, opcode); ret = esdhc_send_tuning_cmd(host, opcode, &sg);
esdhc_post_tuning(host); esdhc_post_tuning(host);
kfree(tuning_pattern);
dev_dbg(mmc_dev(host->mmc), "tunning %s at 0x%x ret %d\n", dev_dbg(mmc_dev(host->mmc), "tunning %s at 0x%x ret %d\n",
ret ? "failed" : "passed", avg, ret); ret ? "failed" : "passed", avg, ret);