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Date: Wed, 29 Jan 2014 16:50:52 +0100
From: Alexandre COFFIGNAL <acoffignal@geral.com>
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Subject: Re: [Xenomai] imx28 rtcan flexcan system freezes
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Le 29/01/2014 08:16, Wolfgang Grandegger a écrit :
> On Tue, 28 Jan 2014 23:06:54 +0100, Gilles Chanteperdrix
> <gilles.chanteperdrix@xenomai.org> wrote:
>> On 01/27/2014 08:56 AM, Wolfgang Grandegger wrote:
>>> On Sun, 26 Jan 2014 21:56:10 +0100, Gilles Chanteperdrix
>>>> IMO, it is not just for the flexcan driver, it will avoid unaligned
>>>> accesses for all drivers which access data 4 bytes at a time. And I do
>>>> not think it "breaks" anything. What I do not know is:
>>>
>>>
>>> But it's just the Flexcan driver which is doing unaligned accesses.
>> Ok, can we agree on the following patch then?
>>
>> diff --git a/ksrc/drivers/can/rtcan_flexcan.c
>> b/ksrc/drivers/can/rtcan_flexcan.c
>> index 8f0e8d1..1674b73 100644
>> --- a/ksrc/drivers/can/rtcan_flexcan.c
>> +++ b/ksrc/drivers/can/rtcan_flexcan.c
>> @@ -38,6 +38,7 @@
>>   #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0)
>>   #include <linux/pinctrl/consumer.h>
>>   #endif
>> +#include <asm/unaligned.h>
>>   
>>   #include <rtdm/rtdm_driver.h>
>>   
>> @@ -497,11 +498,9 @@ static void flexcan_rx_interrupt(struct
> rtcan_device
>> *dev,
>>   		cf->can_id |= CAN_RTR_FLAG;
>>   		skb->rb_frame_size = EMPTY_RB_FRAME_SIZE;
>>   	} else {
>> -		skb->rb_frame_size = EMPTY_RB_FRAME_SIZE + cf->can_dlc ;
>> -		*(__be32 *)(cf->data + 0) =
>> -			cpu_to_be32(flexcan_read(&mb->data[0]));
>> -		*(__be32 *)(cf->data + 4) =
>> -			cpu_to_be32(flexcan_read(&mb->data[1]));
>> +		skb->rb_frame_size = EMPTY_RB_FRAME_SIZE + cf->can_dlc;
>> +		put_unaligned_be32(flexcan_read(&mb->data[0]), cf->data + 0);
>> +		put_unaligned_be32(flexcan_read(&mb->data[1]), cf->data + 4);
>>   	}
>>   
>>   	/* Store the interface index */
> D'accord, thanks.
>
> Wolfgang.
>
Thank you all for your replies

Alexandre.