[PATCH 4.19 05/99] i2c: imx: correct the method of getting private data in notifier_call

From: Greg Kroah-Hartman
Date: Mon May 06 2019 - 10:40:38 EST


From: Anson Huang <anson.huang@xxxxxxx>

commit d386bb9042f4629bf62cdc5952ea8aab225f24a7 upstream.

The way of getting private imx_i2c_struct in i2c_imx_clk_notifier_call()
is incorrect, should use clk_change_nb element to get correct address
and avoid below kernel dump during POST_RATE_CHANGE notify by clk
framework:

Unable to handle kernel paging request at virtual address 03ef1488
pgd = (ptrval)
[03ef1488] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Workqueue: events reduce_bus_freq_handler
PC is at i2c_imx_set_clk+0x10/0xb8
LR is at i2c_imx_clk_notifier_call+0x20/0x28
pc : [<806a893c>] lr : [<806a8a04>] psr: a0080013
sp : bf399dd8 ip : bf3432ac fp : bf7c1dc0
r10: 00000002 r9 : 00000000 r8 : 00000000
r7 : 03ef1480 r6 : bf399e50 r5 : ffffffff r4 : 00000000
r3 : bf025300 r2 : bf399e50 r1 : 00b71b00 r0 : bf399be8
Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 10c5387d Table: 4e03004a DAC: 00000051
Process kworker/2:1 (pid: 38, stack limit = 0x(ptrval))
Stack: (0xbf399dd8 to 0xbf39a000)
9dc0: 806a89e4 00000000
9de0: ffffffff bf399e50 00000002 806a8a04 806a89e4 80142900 ffffffff 00000000
9e00: bf34ef18 bf34ef04 00000000 ffffffff bf399e50 80142d84 00000000 bf399e6c
9e20: bf34ef00 80f214c4 bf025300 00000002 80f08d08 bf017480 00000000 80142df0
9e40: 00000000 80166ed8 80c27638 8045de58 bf352340 03ef1480 00b71b00 0f82e242
9e60: bf025300 00000002 03ef1480 80f60e5c 00000001 8045edf0 00000002 8045eb08
9e80: bf025300 00000002 03ef1480 8045ee10 03ef1480 8045eb08 bf01be40 00000002
9ea0: 03ef1480 8045ee10 07de2900 8045eb08 bf01b780 00000002 07de2900 8045ee10
9ec0: 80c27898 bf399ee4 bf020a80 00000002 1f78a400 8045ee10 80f60e5c 80460514
9ee0: 80f60e5c bf01b600 bf01b480 80460460 0f82e242 bf383a80 bf383a00 80f60e5c
9f00: 00000000 bf7c1dc0 80f60e70 80460564 80f60df0 80f60d24 80f60df0 8011e72c
9f20: 00000000 80f60df0 80f60e6c bf7c4f00 00000000 8011e7ac bf274000 8013bd84
9f40: bf7c1dd8 80f03d00 bf274000 bf7c1dc0 bf274014 bf7c1dd8 80f03d00 bf398000
9f60: 00000008 8013bfb4 00000000 bf25d100 bf25d0c0 00000000 bf274000 8013bf88
9f80: bf25d11c bf0cfebc 00000000 8014140c bf25d0c0 801412ec 00000000 00000000
9fa0: 00000000 00000000 00000000 801010e8 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[<806a893c>] (i2c_imx_set_clk) from [<806a8a04>] (i2c_imx_clk_notifier_call+0x20/0x28)
[<806a8a04>] (i2c_imx_clk_notifier_call) from [<80142900>] (notifier_call_chain+0x44/0x84)
[<80142900>] (notifier_call_chain) from [<80142d84>] (__srcu_notifier_call_chain+0x44/0x98)
[<80142d84>] (__srcu_notifier_call_chain) from [<80142df0>] (srcu_notifier_call_chain+0x18/0x20)
[<80142df0>] (srcu_notifier_call_chain) from [<8045de58>] (__clk_notify+0x78/0xa4)
[<8045de58>] (__clk_notify) from [<8045edf0>] (__clk_recalc_rates+0x60/0xb4)
[<8045edf0>] (__clk_recalc_rates) from [<8045ee10>] (__clk_recalc_rates+0x80/0xb4)
Code: e92d40f8 e5903298 e59072a0 e1530001 (e5975008)
---[ end trace fc7f5514b97b6cbb ]---

Fixes: 90ad2cbe88c2 ("i2c: imx: use clk notifier for rate changes")
Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
Reviewed-by: Dong Aisheng <aisheng.dong@xxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/i2c/busses/i2c-imx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -510,9 +510,9 @@ static int i2c_imx_clk_notifier_call(str
unsigned long action, void *data)
{
struct clk_notifier_data *ndata = data;
- struct imx_i2c_struct *i2c_imx = container_of(&ndata->clk,
+ struct imx_i2c_struct *i2c_imx = container_of(nb,
struct imx_i2c_struct,
- clk);
+ clk_change_nb);

if (action & POST_RATE_CHANGE)
i2c_imx_set_clk(i2c_imx, ndata->new_rate);