| Message ID | 1384410351-2169-2-git-send-email-b32955@freescale.com |
|---|---|
| State | Accepted |
| Commit | df877fb3f51980e60f785bb85ab841a5df01dc26 |
| Headers | show |
On Thu, Nov 14, 2013 at 02:25:44PM +0800, Huang Shijie wrote: > 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 <b32955@freescale.com> > --- > drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 9 ++++++++- > 1 files changed, 8 insertions(+), 1 deletions(-) > > 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 <linux/delay.h> > #include <linux/clk.h> > +#include <linux/slab.h> > > #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; > ONFI_SUBFEATURE_PARAM_LEN is only 4, so the most natural choice is to allocate that in the stack. I think you should add a comment here explaining that this buffer needs to be kmallocated for dma purposes. Just a nitpick, to avoid people asking why you're doing the allocation for just 4 bytes. > + 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; > } > -- > 1.7.2.rc3 > > > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/
On Thu, 2013-11-14 at 22:53 -0500, Huang Shijie wrote:
> ...
Huang, your system clock is *still* set incorrectly, and your messages
are claiming to have been sent from 11 hours in the future.
Unfortunately, a number of email clients sort on the time which a
message claims to have been sent, rather than the time it was actually
received (which would make much more sense). So your clock
misconfiguration makes these threads appear permanently at the bottom of
a mailbox... to the detriment of other active conversations. It confuses
the Android mailer so much that it keeps telling me I have *new* mail
from you, over and over again.
Please could you fix your clock?
You *didn't* actually send that message through a time machine from
22:53 US Eastern Time as it claims, did you?
于 2013年11月15日 00:23, David Woodhouse 写道:
> Please could you fix your clock?
ok, i will fix the clock.
thanks
Huang Shijie
On Thu, Nov 14, 2013 at 10:46:31AM -0300, Ezequiel Garcia wrote: > On Thu, Nov 14, 2013 at 02:25:44PM +0800, Huang Shijie wrote: > > ONFI_SUBFEATURE_PARAM_LEN is only 4, so the most natural choice is to > allocate that in the stack. I think you should add a comment here > explaining that this buffer needs to be kmallocated for dma purposes. > > Just a nitpick, to avoid people asking why you're doing the allocation > for just 4 bytes. i just do not like the warning. thanks Huang Shijie
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 <linux/delay.h> #include <linux/clk.h> +#include <linux/slab.h> #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; }
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 <b32955@freescale.com> --- drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-)