RE: [PATCH 4/6] net: can: flexcan: Add provision for variable payload size

[Pankaj Bansal <pankaj.bansal@xxxxxxx>]

> -----Original Message-----
> From: Marc Kleine-Budde [mailto:mkl@xxxxxxxxxxxxxx]
> Sent: Tuesday, July 31, 2018 12:47 PM
> To: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>; Pankaj
> Bansal <pankaj.bansal@xxxxxxx>
> Cc: linux-can@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 4/6] net: can: flexcan: Add provision for variable
> payload size
> 
> On 07/31/2018 07:34 AM, Alexander Stein wrote:
> > On Monday, July 30, 2018, 6:07:13 PM CEST Pankaj Bansal wrote:
> >> [...]
> >> @@ -666,8 +670,13 @@ static unsigned int
> flexcan_mailbox_read(struct
> >> can_rx_offload *offload,  {
> >>  	struct flexcan_priv *priv = rx_offload_to_priv(offload);
> >>  	struct flexcan_regs __iomem *regs = priv->regs;
> >> -	struct flexcan_mb __iomem *mb = &regs->mb[n];
> >> -	u32 reg_ctrl, reg_id, reg_iflag1;
> >> +	struct flexcan_mb __iomem *mb;
> >> +	u32 reg_ctrl, reg_id, reg_iflag1, i, data;
> >
> > Shouldn't data be __be32 instead?
> 
> Yes...
> 
> >
> >> +	u8 mb_size, can_dlc_dword;
> >> +
> >> +	mb_size = sizeof(struct flexcan_mb) +
> >> +priv->devtype_data->payload_size;
> >> +
> >> +	mb = (struct flexcan_mb __iomem *)((u8 *)&regs->mb + (mb_size
> *
> >> +n));
> >>
> >>  	if (priv->devtype_data->quirks &
> FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
> >>  		u32 code;
> >> @@ -708,8 +717,11 @@ static unsigned int
> flexcan_mailbox_read(struct can_rx_offload *offload,
> >>  		cf->can_id |= CAN_RTR_FLAG;
> >>  	cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
> >>
> >> -	*(__be32 *)(cf->data + 0) = cpu_to_be32(priv->read(&mb-
> >data[0]));
> >> -	*(__be32 *)(cf->data + 4) = cpu_to_be32(priv->read(&mb-
> >data[1]));
> >> +	can_dlc_dword = (cf->can_dlc + sizeof(u32) - 1) / sizeof(u32);
> >> +	for (i = 0; i < can_dlc_dword; i++) {
> >> +		data = cpu_to_be32(priv->read(&mb->data[i]));
> 
> ...as it's assigned from a _to_be32 here.

Understood. Will incorporate in V2

> 
> >> +		*(__be32 *)(cf->data + (i * sizeof(u32))) = data;
> >
> > So sparse can help here when dealing with little/big-endianess when
> compiling using C=2.
> ACK
> 
> Marc
> 
> --
> Pengutronix e.K.                  | Marc Kleine-Budde           |
> Industrial Linux Solutions        | Phone: +49-231-2826-924     |
> Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
> Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |

��.n��������+%������w��{.n�����{����*jg��������ݢj����G�������j:+v���w�m������w�������h�����٥