imprecise external abort using the flexcan driver on i.MX6Q

[Marc Kleine-Budde]

On 09/27/2013 04:32 PM, Lothar Waßmann wrote:
> Hi,
> 
> Fabio Estevam writes:
>> Hi Lothar,
>>
>> On Thu, Sep 26, 2013 at 11:01 AM, Lothar Waßmann
>> <LW at karo-electronics.de> wrote:
>>> Does anyone have any clue how this can happen?
>>>
>>> Can anyone reproduce this on another machine?
>>
>> Is the change below needed?
>>
>> --- a/arch/arm/boot/dts/imx6qdl.dtsi
>> +++ b/arch/arm/boot/dts/imx6qdl.dtsi
>> @@ -310,7 +310,7 @@
>>                         };
>>
>>                         can1: flexcan at 02090000 {
>> -                               compatible = "fsl,imx6q-flexcan";
>> +                               compatible = "fsl,imx6q-flexcan",
>> "fsl,p1010-flexcan";
>>                                 reg = <0x02090000 0x4000>;
>>                                 interrupts = <0 110 0x04>;
>>                                 clocks = <&clks 108>, <&clks 109>;
>> @@ -318,7 +318,7 @@
>>                         };
>>
>>                         can2: flexcan at 02094000 {
>> -                               compatible = "fsl,imx6q-flexcan";
>> +                               compatible = "fsl,imx6q-flexcan",
>> "fsl,p1010-flexcan";
>>                                 reg = <0x02094000 0x4000>;
>>                                 interrupts = <0 111 0x04>;
>>                                 clocks = <&clks 110>, <&clks 111>;
> The driver contains:
> |static const struct of_device_id flexcan_of_match[] = {
> |	{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
> |	{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
> |	{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
> |	{ /* sentinel */ },
> 
> Thus, with your proposed change the DT data would become ambiguous and
> the driver might use &fsl_p1010_devtype_data rather than
> &fsl_imx6q_devtype_data depending how the matching algorithm works.

In fact the imx6 flexcan is not compatible with the p1010, as a certain
register on the imx6 must be written to let the driver work.

Marc
-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
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