[PATCH] pinctrl: imx1-core: Fix debug output pin array index

[chris.ruehl@gtsys.com.hk (Chris Ruehl)]

Uwe,

On Thursday, July 09, 2015 03:12 PM, Uwe Kleine-K?nig wrote:
> Hello Markus,
>
> Cc += Chris Ruehl
>
> On Wed, Jul 08, 2015 at 04:16:06PM +0200, Markus Pargmann wrote:
>> The pins do not have a 1:1 mapping from index to pin_id. Unfortunately
>> the debug output assumes exactly that.
>>
>> The first driver using imx1-core was imx27, which had exactly this 1:1
>> mapping. It was accidently removed when removing all unused pads which
>> were listed:
>> 	607af165c047 (pinctrl: i.MX27: Remove nonexistent pad definitions)
>>
>> The patch fixes this issue by printing the pin_id directly and not the
>> pin name.
> Knowing a bit about the imx pinctrl drivers I failed to understand what
> you wrote here. Probably because I first though that "1:1 mapping" is a
> hardware property. What about:
>
> 	Subject: pinctrl: imx1-core: Fix debug output in .pin_config_set callback
>
> 	imx1_pinconf_set assumes that the array of pins in struct
> 	imx1_pinctrl_soc_info can be indexed by pin id to get the
> 	pinctrl_pin_desc for a pin. This used to be correct up to commit
> 	607af165c047 ("pinctrl: i.MX27: Remove nonexistent pad definitions")
> 	which removed some entries from the array and so made it wrong to access
> 	the array by pin id.
>
> 	Implement the easiest fix by not resolving the pin id to a name but
> 	printing the id instead.
>
> 	Fixes: 607af165c047 ("pinctrl: i.MX27: Remove nonexistent pad definitions")
> 	Cc: stable at vger.kernel.org
> 	Reported-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
> 	Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
>
> Having the pad name in the output is nice, is it worth to search for the
> right pinctrl_pin_desc in the array? The array is still sorted, so a
> binary search would do, maybe a function for this already exists?
>
> How did Chris notice the error? Just a bogus output, or did it crash the
> kernel? That would be worth to note in the commit log, too.
>
> Otherwise the change looks fine.
>
> Best regards
> Uwe

I had a crash on a array overrun.

I'd applied a patch to the linux-usb (which was spit out by the maintainer perl 
script)
chris at wheezyvm:~/kernel.d/linux-next$ cat 
0001-Pinctrl-imx1-fix-wrong-pin-name-resolving.patch
 From 50d56e5f626b2ea86211818cf487514c96f60487 Mon Sep 17 00:00:00 2001
From: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Date: Sat, 23 May 2015 15:02:44 +0800
Subject: [PATCH] Pinctrl: imx1: fix wrong pin-name resolving

Bug in function imx1_pinconf_set() cause crash when
princtrl debug is enabled and the pin_id becomes larger
then the info->pins[] contains.

imx27-pinctrl 10015000.iomuxc: request pin 134 (MX27_PAD_UART2_TXD) for 
1000b000.serial
imx27-pinctrl 10015000.iomuxc: request pin 135 (MX27_PAD_UART2_RXD) for 
1000b000.serial
imx27-pinctrl 10015000.iomuxc: request pin 131 (MX27_PAD_UART2_CTS) for 
1000b000.serial
imx27-pinctrl 10015000.iomuxc: request pin 132 (MX27_PAD_UART2_RTS) for 
1000b000.serial
imx27-pinctrl 10015000.iomuxc: enable function uart group uart2-1
imx27-pinctrl 10015000.iomuxc: imx1_pmx_set, pin 0x86, function 0, gpio 0, 
direction 1, oconf 0, iconfa 0, iconfb 0
imx27-pinctrl 10015000.iomuxc: imx1_pmx_set, pin 0x87, function 0, gpio 0, 
direction 0, oconf 0, iconfa 0, iconfb 0
imx27-pinctrl 10015000.iomuxc: imx1_pmx_set, pin 0x83, function 0, gpio 0, 
direction 1, oconf 0, iconfa 0, iconfb 0
imx27-pinctrl 10015000.iomuxc: imx1_pmx_set, pin 0x84, function 0, gpio 0, 
direction 0, oconf 0, iconfa 0, iconfb 0
imx27-pinctrl 10015000.iomuxc: num_configs=1 PinID=134
imx27-pinctrl 10015000.iomuxc: pinconf set pullup pin MX27_PAD_UART1_RTS
imx27-pinctrl 10015000.iomuxc: num_configs=1 PinID=135
imx27-pinctrl 10015000.iomuxc: pinconf set pullup pin MX27_PAD_RTCK
imx27-pinctrl 10015000.iomuxc: num_configs=1 PinID=131
imx27-pinctrl 10015000.iomuxc: pinconf set pullup pin MX27_PAD_UART1_TXD
imx27-pinctrl 10015000.iomuxc: num_configs=1 PinID=132
imx27-pinctrl 10015000.iomuxc: pinconf set pullup pin MX27_PAD_UART1_RXD
...
imx27-pinctrl 10015000.iomuxc: write: register 0xf4415508 offset 4 value 0x3
imx27-pinctrl 10015000.iomuxc: write: register 0xf4415510 offset 4 value 0x0
imx27-pinctrl 10015000.iomuxc: write: register 0xf4415518 offset 4 value 0x0
imx27-pinctrl 10015000.iomuxc: imx1_pmx_set, pin 0xb5, function 0, gpio 0, 
direction 1, oconf 0, iconfa 0, iconfb 0
imx27-pinctrl 10015000.iomuxc: num_configs=1 PinID=171
Unable to handle kernel paging request at virtual address 6c61765f
pgd = c0004000
6c61765f] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.1.0-rc4-next-20150522-dirty #8
Hardware name: GTSYS i.MX27GTSIR (Device Tree Support)
task: ce832000 ti: ce848000 task.ti: ce848000
PC is at strnlen+0x28/0x3c
LR is at string.isra.4+0x34/0xcc
pc : [<c01ae188>]    lr : [<c01af9a4>]    psr: 20000093
sp : ce849a88  ip : ce849a98  fp : ce849a94
r10: c05d7e3a  r9 : c05d81e4  r8 : 00000000
r7 : 6c61765f  r6 : c05d81e4  r5 : ffffffff  r4 : c05d7e3a
r3 : 6c61765f  r2 : 6c61765f  r1 : 6c61765e  r0 : 6c61765f
Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel


Signed-off-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
---
  drivers/pinctrl/freescale/pinctrl-imx1-core.c |    6 ++++--
  1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/freescale/pinctrl-imx1-core.c 
b/drivers/pinctrl/freescale/pinctrl-imx1-core.c
index 5ac59fb..8408bd8 100644
--- a/drivers/pinctrl/freescale/pinctrl-imx1-core.c
+++ b/drivers/pinctrl/freescale/pinctrl-imx1-core.c
@@ -403,14 +403,16 @@ static int imx1_pinconf_set(struct pinctrl_dev *pctldev,
  			     unsigned num_configs)
  {
  	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
-	const struct imx1_pinctrl_soc_info *info = ipctl->info;
+	struct pin_desc *desc;
  	int i;

+	desc = pin_desc_get(pctldev, pin_id);
+
  	for (i = 0; i != num_configs; ++i) {
  		imx1_write_bit(ipctl, pin_id, configs[i] & 0x01, MX1_PUEN);

  		dev_dbg(ipctl->dev, "pinconf set pullup pin %s\n",
-			info->pins[pin_id].name);
+			desc->name);
  	}

  	return 0;
-- 
1.7.10.4




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