mtd: gpmi: fix the NULL pointer
commit
885d71e5838f68d5dbee92ab952cc90ad6c1dc6b upstream.
The imx23 board will check the fingerprint, so it will call the
mx23_check_transcription_stamp. This function will use @chip->buffers->databuf
as its buffer which is allocated in the nand_scan_tail().
Unfortunately, the mx23_check_transcription_stamp is called before the
nand_scan_tail(). So we will meet a NULL pointer bug:
--------------------------------------------------------------------
[ 1.150000] NAND device: Manufacturer ID: 0xec, Chip ID: 0xd7 (Samsung NAND 4GiB 3,3V 8-bit), 4096MiB, page size: 4096, OOB size: 8
[ 1.160000] Unable to handle kernel NULL pointer dereference at virtual address
000005d0
[ 1.170000] pgd =
c0004000
[ 1.170000] [
000005d0] *pgd=
00000000
[ 1.180000] Internal error: Oops: 5 [#1] ARM
[ 1.180000] Modules linked in:
[ 1.180000] CPU: 0 PID: 1 Comm: swapper Not tainted 3.12.0 #89
[ 1.180000] task:
c7440000 ti:
c743a000 task.ti:
c743a000
[ 1.180000] PC is at memcmp+0x10/0x54
[ 1.180000] LR is at gpmi_nand_probe+0x42c/0x894
[ 1.180000] pc : [<
c025fcb0>] lr : [<
c02f6a68>] psr:
20000053
[ 1.180000] sp :
c743be2c ip :
600000d3 fp :
ffffffff
[ 1.180000] r10:
000005d0 r9 :
c02f5f08 r8 :
00000000
[ 1.180000] r7 :
c75858a8 r6 :
c75858a8 r5 :
c7585b18 r4 :
c7585800
[ 1.180000] r3 :
000005d0 r2 :
00000004 r1 :
c05c33e4 r0 :
000005d0
[ 1.180000] Flags: nzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel
[ 1.180000] Control:
0005317f Table:
40004000 DAC:
00000017
[ 1.180000] Process swapper (pid: 1, stack limit = 0xc743a1c0)
--------------------------------------------------------------------
This patch rearrange the init procedure:
Set the NAND_SKIP_BBTSCAN to skip the nand scan firstly, and after we
set the proper settings, we will call the chip->scan_bbt() manually.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Reported-by: Fabio Estevam <festevam@gmail.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>