From 9d2fc80fb15b99736ecd1895934ce4512e76fa3f Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 25 Apr 2014 12:59:00 +0100 Subject: [PATCH] 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 Tested-by: Markus Pargmann Tested-by: Stephen Warren Signed-off-by: Ulf Hansson Signed-off-by: Chris Ball --- drivers/mmc/host/sdhci-esdhc-imx.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index ce8939ff97a4..5acfe2fc4fe0 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); -- 2.34.1