Hello all,
I'm working on "T.I Davinci EVM, DM6467 processor". This EVM has multiple PHYs. I need to be able to edit register settings of the PHYs once the kernel is up, i.e. I'm trying to write a character driver which takes device address, register address and data to be written from user-application and does an MDIO read/write. In the driver ioctl, I use/call the functions "emac_mdio_read" and "emac_mdio_write" defined in "drivers/net/davinci_emac_phy.c" (I'm using kernel version 2.6.18) The module compiles and insmod also succeeds, but when I run it, I get the following error:
Code:
root@192.168.37.179:/# ./i2c_mdio_testapp.out
<1>
Unable to handle kernel NULL pointer dereference at virtual address 00000080
pgd = c3ddc000
[00000080] *pgd=8431f031, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#2]
Modules linked in: ittiam_i2c_mdio_regrw
CPU: 0
PC is at emac_mdio_read+0x3c/0x9c [ittiam_i2c_mdio_regrw]
LR is at 0x1
pc : [<bf0004ec>] lr : [<00000001>] Not tainted
sp : c3dd9ef0 ip : 60000093 fp : c3dd9f0c
r10: 00000000 r9 : c3dd8000 r8 : 00000003
r7 : c0603aa0 r6 : 0000000a r5 : 00000001 r4 : bf0032f0
r3 : 00000080 r2 : 00000000 r1 : 00000080 r0 : 00000036
Flags: nZCv IRQs on FIQs on Mode SVC_32 Segment user
Control: 5317F
Table: 83DDC000 DAC: 00000015
Process i2c_mdio_testap (pid: 946, stack limit = 0xc3dd8258)
Stack: (0xc3dd9ef0 to 0xc3dda000)
9ee0: c3dd9f24 c0603aa0 00010708 00000001
9f00: c3dd9f24 c3dd9f10 bf001318 bf0004c0 c0603aa0 00010708 c3dd9f44 c3dd9f28
9f20: c00a7eec bf0012dc c0065d38 c0603aa0 00000003 00010708 c3dd9f74 c3dd9f48
9f40: c00a81cc c00a7e80 00000003 00000000 00000000 00000000 00010708 00000001
9f60: 00000003 c3dd8000 c3dd9fa4 c3dd9f78 c00a82a8 c00a7f18 c3dd9f9c 00000000
9f80: c003ce94 40024e00 00000000 00000000 00000036 c0035fa8 00000000 c3dd9fa8
9fa0: c0035f78 c00a8204 40024e00 00000000 00000003 00000001 00010708 00000003
9fc0: 40024e00 00000000 00000000 00000036 00000000 00000000 40025000 be8dcce4
9fe0: 00000000 be8dccc0 0000849c 400e027c 60000010 00000003 00000000 00000000
Backtrace:
[<bf0004b0>] (emac_mdio_read+0x0/0x9c [ittiam_i2c_mdio_regrw]) from [<bf001318>] (i2c_mdio_regrw_ioctl+0x4c/0x120 [ittiam_i2c_mdio_regrw])
r6 = 00000001 r5 = 00010708 r4 = C0603AA0
[<bf0012cc>] (i2c_mdio_regrw_ioctl+0x0/0x120 [ittiam_i2c_mdio_regrw]) from [<c00a7eec>] (do_ioctl+0x7c/0x98)
r5 = 00010708 r4 = C0603AA0
[<c00a7e70>] (do_ioctl+0x0/0x98) from [<c00a81cc>] (vfs_ioctl+0x2c4/0x2ec)
r6 = 00010708 r5 = 00000003 r4 = C0603A
Could anyone suggest where I'm going on, or is there a ready way using which I can do MDIO Read/Write?..
<I'm sorry, this is not a core networking related issue, but just one involving a network hardware configuration.. Din't know where else this would fit on the forum, so posted it here.. If i'm to post it in a different group, pls redirect me there>
Thank you,
