Re: [PATCH V4 1/3] can: flexcan: initialize all flexcan memory for ECC function

[Marc Kleine-Budde]

On 9/29/20 2:50 PM, Joakim Zhang wrote:
> 
>> -----Original Message-----
>> From: Marc Kleine-Budde <m...@pengutronix.de>
>> Sent: 2020年9月29日 20:46
>> To: Joakim Zhang <qiangqing.zh...@nxp.com>; linux-...@vger.kernel.org
>> Cc: netdev@vger.kernel.org; dl-linux-imx <linux-...@nxp.com>
>> Subject: Re: [PATCH V4 1/3] can: flexcan: initialize all flexcan memory for 
>> ECC
>> function
>>
>> On 9/29/20 2:38 PM, Joakim Zhang wrote:
>>>>>           return flexcan_set_bittiming_ctrl(dev);  }
>>>>>
>>>>> +static void flexcan_init_ram(struct net_device *dev) {
>>>>> + struct flexcan_priv *priv = netdev_priv(dev);
>>>>> + struct flexcan_regs __iomem *regs = priv->regs;
>>>>> + u32 reg_ctrl2;
>>>>> +
>>>>> + /* 11.8.3.13 Detection and correction of memory errors:
>>>>> +  * CTRL2[WRMFRZ] grants write access to all memory positions that
>>>>> +  * require initialization, ranging from 0x080 to 0xADF and
>>>>> +  * from 0xF28 to 0xFFF when the CAN FD feature is enabled.
>>>>> +  * The RXMGMASK, RX14MASK, RX15MASK, and RXFGMASK
>> registers
>>>> need to
>>>>> +  * be initialized as well. MCR[RFEN] must not be set during memory
>>>>> +  * initialization.
>>>>> +  */
>>>>> + reg_ctrl2 = priv->read(&regs->ctrl2);
>>>>> + reg_ctrl2 |= FLEXCAN_CTRL2_WRMFRZ;
>>>>> + priv->write(reg_ctrl2, &regs->ctrl2);
>>>>> +
>>>>> + memset_io(&regs->mb[0][0], 0,
>>>>> +           (u8 *)&regs->rx_smb1[3] - &regs->mb[0][0] + 0x4);
>>>>
>>>> why the cast?
>>>
>>> Due to mb is defined as a u8. And the count of memset_io is bytes.
>>
>> right. this is why you don't need the 2nd cast.
> 
> Yes, do you need me send a patch to improve it with offsetof()?

If it looks better :), then yes :)

Marc

-- 
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