From df877fb3f51980e60f785bb85ab841a5df01dc26 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Thu, 14 Nov 2013 14:25:44 +0800 Subject: [PATCH] mtd: gpmi: do not use the local array to do the DMA transfer The local array feature[] is in the stack. We can see the warning when we enable the CONFIG_DMA_API_DEBUG: ---------------------------------------------------------- WARNING: at lib/dma-debug.c:950 check_for_stack+0xac/0xf8() gpmi-nand 112000.gpmi-nand: DMA-API: device driver maps memory fromstack [addr=dc05be34] Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.17-16851-g2414a73 #1324 [<80014cbc>] (unwind_backtrace+0x0/0x138) from [<8001251c>] (show_stack+0x10/0x14) [<8001251c>] (show_stack+0x10/0x14) from [<8002699c>] (warn_slowpath_common+0x4c/0x68) [<8002699c>] (warn_slowpath_common+0x4c/0x68) from [<80026a4c>] (warn_slowpath_fmt+0x30/0x40) [<80026a4c>] (warn_slowpath_fmt+0x30/0x40) from [<8028e2f8>] (check_for_stack+0xac/0xf8) [<8028e2f8>] (check_for_stack+0xac/0xf8) from [<8028e438>] (debug_dma_map_sg+0xf4/0x188) [<8028e438>] (debug_dma_map_sg+0xf4/0x188) from [<803968d0>] (prepare_data_dma+0xb8/0x1a8) [<803968d0>] (prepare_data_dma+0xb8/0x1a8) from [<80397b20>] (gpmi_send_data+0x84/0xfc) [<80397b20>] (gpmi_send_data+0x84/0xfc) from [<8038c2b4>] (nand_onfi_set_features+0x50/0x74) [<8038c2b4>] (nand_onfi_set_features+0x50/0x74) from [<80397198>] (gpmi_extra_init+0x90/0x170) [<80397198>] (gpmi_extra_init+0x90/0x170) from [<8039520c>] (gpmi_nand_probe+0x2f8/0xb3c) [<8039520c>] (gpmi_nand_probe+0x2f8/0xb3c) from [<8031b974>] (platform_drv_probe+0x18/0x1c) ---------------------------------------------------------- The patch uses the kzalloc to allocate the buffer, and free it when we do not use it anymore. Signed-off-by: Huang Shijie Signed-off-by: Brian Norris --- drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c index c7a578c..10a6f07 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c @@ -20,6 +20,7 @@ */ #include #include +#include #include "gpmi-nand.h" #include "gpmi-regs.h" @@ -911,10 +912,14 @@ static int enable_edo_mode(struct gpmi_nand_data *this, int mode) struct resources *r = &this->resources; struct nand_chip *nand = &this->nand; struct mtd_info *mtd = &this->mtd; - uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {}; + uint8_t *feature; unsigned long rate; int ret; + feature = kzalloc(ONFI_SUBFEATURE_PARAM_LEN, GFP_KERNEL); + if (!feature) + return -ENOMEM; + nand->select_chip(mtd, 0); /* [1] send SET FEATURE commond to NAND */ @@ -942,11 +947,13 @@ static int enable_edo_mode(struct gpmi_nand_data *this, int mode) this->flags |= GPMI_ASYNC_EDO_ENABLED; this->timing_mode = mode; + kfree(feature); dev_info(this->dev, "enable the asynchronous EDO mode %d\n", mode); return 0; err_out: nand->select_chip(mtd, -1); + kfree(feature); dev_err(this->dev, "mode:%d ,failed in set feature.\n", mode); return -EINVAL; } -- 2.7.4