Re: [PATCH net-next-2.6 v2] can: Topcliff: PCH_CAN driver: Fix build warnings

Wolfgang Grandegger
2010-10-29T19:31:15Z

Hello,

some more comments from my side.

On 10/29/2010 06:23 PM, Marc Kleine-Budde wrote:
> Hello,
>
> On 10/29/2010 02:57 PM, Marc Kleine-Budde wrote:
>> The driver has already been merged. Please send incremental patches
>> against david's net-2.6 branch.
>
> Here a review, find comments inline. Lets talk about my remarks, please
> answer inline and don't delete the code.
>
> Can you please explain me your locking sheme? If I understand the
> documenation correctly the two message interfaces can be used mutual.
> And you use one for rx the other one for tx.
>
> Please use netdev_<level> instead of dev_<level> for debug.
>
>> --- /dev/null
>> +++ b/drivers/net/can/pch_can.c
>> @@ -0,0 +1,1436 @@
>> +/*
>> + * Copyright (C) 1999 - 2010 Intel Corporation.
>> + * Copyright (C) 2010 OKI SEMICONDUCTOR CO., LTD.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; version 2 of the License.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, write to the Free Software
>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
>> + */
>> +
>> +#include <linux/interrupt.h>
>> +#include <linux/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/sched.h>
>> +#include <linux/pci.h>
>> +#include <linux/init.h>
>> +#include <linux/kernel.h>
>> +#include <linux/types.h>
>> +#include <linux/errno.h>
>> +#include <linux/netdevice.h>
>> +#include <linux/skbuff.h>
>> +#include <linux/can.h>
>> +#include <linux/can/dev.h>
>> +#include <linux/can/error.h>
>> +
>> +#define MAX_MSG_OBJ 32
>> +#define MSG_OBJ_RX 0 /* The receive message object flag. */
>> +#define MSG_OBJ_TX 1 /* The transmit message object flag. */
>> +
>> +#define CAN_CTRL_INIT 0x0001 /* The INIT bit of CANCONT register. */
>> +#define CAN_CTRL_IE 0x0002 /* The IE bit of CAN control register */
>> +#define CAN_CTRL_IE_SIE_EIE 0x000e
>> +#define CAN_CTRL_CCE 0x0040
>> +#define CAN_CTRL_OPT 0x0080 /* The OPT bit of CANCONT register. */
>> +#define CAN_OPT_SILENT 0x0008 /* The Silent bit of CANOPT reg. */
>> +#define CAN_OPT_LBACK 0x0010 /* The LoopBack bit of CANOPT reg. */
>> +#define CAN_CMASK_RX_TX_SET 0x00f3
>> +#define CAN_CMASK_RX_TX_GET 0x0073
>> +#define CAN_CMASK_ALL 0xff
>> +#define CAN_CMASK_RDWR 0x80
>> +#define CAN_CMASK_ARB 0x20
>> +#define CAN_CMASK_CTRL 0x10
>> +#define CAN_CMASK_MASK 0x40
>> +#define CAN_CMASK_NEWDAT 0x04
>> +#define CAN_CMASK_CLRINTPND 0x08
>> +
>> +#define CAN_IF_MCONT_NEWDAT 0x8000
>> +#define CAN_IF_MCONT_INTPND 0x2000
>> +#define CAN_IF_MCONT_UMASK 0x1000
>> +#define CAN_IF_MCONT_TXIE 0x0800
>> +#define CAN_IF_MCONT_RXIE 0x0400
>> +#define CAN_IF_MCONT_RMTEN 0x0200
>> +#define CAN_IF_MCONT_TXRQXT 0x0100
>> +#define CAN_IF_MCONT_EOB 0x0080
>> +#define CAN_IF_MCONT_DLC 0x000f
>> +#define CAN_IF_MCONT_MSGLOST 0x4000
>> +#define CAN_MASK2_MDIR_MXTD 0xc000
>> +#define CAN_ID2_DIR 0x2000
>> +#define CAN_ID_MSGVAL 0x8000
>> +
>> +#define CAN_STATUS_INT 0x8000
>> +#define CAN_IF_CREQ_BUSY 0x8000
>> +#define CAN_ID2_XTD 0x4000
>> +
>> +#define CAN_REC 0x00007f00
>> +#define CAN_TEC 0x000000ff
>
> A prefix for like PCH_ instead of CAN_ for all those define above would
> be fine to avoid namespace clashes and/or confusion with the defines from the socketcan framework.
>
>> +
>> +#define PCH_RX_OK 0x00000010
>> +#define PCH_TX_OK 0x00000008
>> +#define PCH_BUS_OFF 0x00000080
>> +#define PCH_EWARN 0x00000040
>> +#define PCH_EPASSIV 0x00000020
>> +#define PCH_LEC0 0x00000001
>> +#define PCH_LEC1 0x00000002
>> +#define PCH_LEC2 0x00000004
>
> These are just single set bit, please use BIT()
> Consider adding the name of the corresponding register to the define's
> name.
>
>> +#define PCH_LEC_ALL (PCH_LEC0 | PCH_LEC1 | PCH_LEC2)
>> +#define PCH_STUF_ERR PCH_LEC0
>> +#define PCH_FORM_ERR PCH_LEC1
>> +#define PCH_ACK_ERR (PCH_LEC0 | PCH_LEC1)
>> +#define PCH_BIT1_ERR PCH_LEC2
>> +#define PCH_BIT0_ERR (PCH_LEC0 | PCH_LEC2)
>> +#define PCH_CRC_ERR (PCH_LEC1 | PCH_LEC2)

This is an enumeration:

enum {
PCH_STUF_ERR = 1,
PCH_FORM_ERR,
PCH_ACK_ERR,
PCH_BIT1_ERR;
PCH_BIT0_ERR,
PCH_CRC_ERR,
PCH_LEC_ALL;
}

Also, s/PCH_/PCH_LEC_/ would be nice.

>> +/* bit position of certain controller bits. */
>> +#define BIT_BITT_BRP 0
>> +#define BIT_BITT_SJW 6
>> +#define BIT_BITT_TSEG1 8
>> +#define BIT_BITT_TSEG2 12
>> +#define BIT_IF1_MCONT_RXIE 10
>> +#define BIT_IF2_MCONT_TXIE 11
>> +#define BIT_BRPE_BRPE 6
>> +#define BIT_ES_TXERRCNT 0
>> +#define BIT_ES_RXERRCNT 8
>
> these are usually called SHIFT
>
>> +#define MSK_BITT_BRP 0x3f
>> +#define MSK_BITT_SJW 0xc0
>> +#define MSK_BITT_TSEG1 0xf00
>> +#define MSK_BITT_TSEG2 0x7000
>> +#define MSK_BRPE_BRPE 0x3c0
>> +#define MSK_BRPE_GET 0x0f
>> +#define MSK_CTRL_IE_SIE_EIE 0x07
>> +#define MSK_MCONT_TXIE 0x08
>> +#define MSK_MCONT_RXIE 0x10
>
> MSK or MASK is okay, however the last two are just single bits.
>
> Please add a PCH_ prefix here, too.
>
>> +#define PCH_CAN_NO_TX_BUFF 1
>> +#define COUNTER_LIMIT 10
>
> dito
>
>> +
>> +#define PCH_CAN_CLK 50000000 /* 50MHz */
>> +
>> +/*
>> + * Define the number of message object.
>> + * PCH CAN communications are done via Message RAM.
>> + * The Message RAM consists of 32 message objects.
>> + */
>> +#define PCH_RX_OBJ_NUM 26 /* 1~ PCH_RX_OBJ_NUM is Rx*/
>> +#define PCH_TX_OBJ_NUM 6 /* PCH_RX_OBJ_NUM is RX ~ Tx*/
>> +#define PCH_OBJ_NUM (PCH_TX_OBJ_NUM + PCH_RX_OBJ_NUM)
>
> You define MAX_MSG_OBJ earlier, seems like two names for the same value.
>
>> +
>> +#define PCH_FIFO_THRESH 16
>> +
>> +enum pch_can_mode {
>> + PCH_CAN_ENABLE,
>> + PCH_CAN_DISABLE,
>> + PCH_CAN_ALL,
>> + PCH_CAN_NONE,
>> + PCH_CAN_STOP,
>> + PCH_CAN_RUN,
>> +};
>> +
>> +struct pch_can_regs {
>> + u32 cont;
>> + u32 stat;
>> + u32 errc;
>> + u32 bitt;
>> + u32 intr;
>> + u32 opt;
>> + u32 brpe;
>> + u32 reserve1;
>
> VVVV
>> + u32 if1_creq;
>> + u32 if1_cmask;
>> + u32 if1_mask1;
>> + u32 if1_mask2;
>> + u32 if1_id1;
>> + u32 if1_id2;
>> + u32 if1_mcont;
>> + u32 if1_dataa1;
>> + u32 if1_dataa2;
>> + u32 if1_datab1;
>> + u32 if1_datab2;
> ^^^^
>
> these registers and....
>
>> + u32 reserve2;
>> + u32 reserve3[12];
>
> ...and these
>
> VVVV
>> + u32 if2_creq;
>> + u32 if2_cmask;
>> + u32 if2_mask1;
>> + u32 if2_mask2;
>> + u32 if2_id1;
>> + u32 if2_id2;
>> + u32 if2_mcont;
>> + u32 if2_dataa1;
>> + u32 if2_dataa2;
>> + u32 if2_datab1;
>> + u32 if2_datab2;
>
> ^^^^
>
> ...are identical. I suggest to make a struct defining a complete
> "Message Interface Register Set". If you include the correct number of
> reserved bytes in the struct, you can have an array of two of these
> structs in the struct pch_can_regs.

Yep, that would be nice. Using it consequently would also allow to
remove duplicated code efficiently. I will name it "struct pch_can_if"
for latter references.

>
>> + u32 reserve4;
>> + u32 reserve5[20];
>> + u32 treq1;
>> + u32 treq2;
>> + u32 reserve6[2];
>> + u32 reserve7[56];
>> + u32 reserve8[3];

Why not just one reserveX ?

>> + u32 srst;
>> +};
>> +
>> +struct pch_can_priv {
>> + struct can_priv can;
>> + struct pci_dev *dev;
>> + unsigned int tx_enable[MAX_MSG_OBJ];
>> + unsigned int rx_enable[MAX_MSG_OBJ];
>> + unsigned int rx_link[MAX_MSG_OBJ];
>> + unsigned int int_enables;
>> + unsigned int int_stat;
>> + struct net_device *ndev;
>> + spinlock_t msgif_reg_lock; /* Message Interface Registers Access Lock*/
> ^^^
> please add a whitespace
>
>> + unsigned int msg_obj[MAX_MSG_OBJ];
>> + struct pch_can_regs __iomem *regs;
>> + struct napi_struct napi;
>> + unsigned int tx_obj; /* Point next Tx Obj index */
>> + unsigned int use_msi;
>> +};
>> +
>> +static struct can_bittiming_const pch_can_bittiming_const = {
>> + .name = "pch_can",
>> + .tseg1_min = 1,
>> + .tseg1_max = 16,
>> + .tseg2_min = 1,
>> + .tseg2_max = 8,
>> + .sjw_max = 4,
>> + .brp_min = 1,
>> + .brp_max = 1024, /* 6bit + extended 4bit */
>> + .brp_inc = 1,
>> +};
>> +
>> +static DEFINE_PCI_DEVICE_TABLE(pch_pci_tbl) = {
>> + {PCI_VENDOR_ID_INTEL, 0x8818, PCI_ANY_ID, PCI_ANY_ID,},
>> + {0,}
>> +};
>> +MODULE_DEVICE_TABLE(pci, pch_pci_tbl);
>> +
>> +static inline void pch_can_bit_set(u32 *addr, u32 mask)
> ^^^^^
>
> that should be an void __iomem *, see mail I've send the other day.
> Please use sparse to check for this kinds of errors.
> (Compile the driver with C=2, i.e.: make drivers/net/can/pch_can.ko C=2)
>
>> +{
>> + iowrite32(ioread32(addr) | mask, addr);
>> +}
>> +
>> +static inline void pch_can_bit_clear(u32 *addr, u32 mask)
> ^^^^^
>
> dito
>
>> +{
>> + iowrite32(ioread32(addr) & ~mask, addr);
>> +}
>> +
>> +static void pch_can_set_run_mode(struct pch_can_priv *priv,
>> + enum pch_can_mode mode)
>> +{
>> + switch (mode) {
>> + case PCH_CAN_RUN:
>> + pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_INIT);
>> + break;
>> +
>> + case PCH_CAN_STOP:
>> + pch_can_bit_set(&priv->regs->cont, CAN_CTRL_INIT);
>> + break;
>> +
>> + default:
>> + dev_err(&priv->ndev->dev, "%s -> Invalid Mode.\n", __func__);
>> + break;
>> + }
>> +}
>> +
>> +static void pch_can_set_optmode(struct pch_can_priv *priv)
>> +{
>> + u32 reg_val = ioread32(&priv->regs->opt);
>> +
>> + if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
>> + reg_val |= CAN_OPT_SILENT;
>> +
>> + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
>> + reg_val |= CAN_OPT_LBACK;
>> +
>> + pch_can_bit_set(&priv->regs->cont, CAN_CTRL_OPT);
>> + iowrite32(reg_val, &priv->regs->opt);
>> +}
>> +
>
> IMHO the function name is missleading, if I understand the code
> correctly, this functions triggers the transmission of the message.
> After this it checks for busy, but
>
>> +static void pch_can_check_if_busy(u32 __iomem *creq_addr, u32 num)
> ^^^^
>
> that should probaby be a void

With separate structs for if1 and i2, a pointer to the relevant "struct
pch_can_if" could be passed instead.

>> +{
>> + u32 counter = COUNTER_LIMIT;
>> + u32 ifx_creq;
>> +
>> + iowrite32(num, creq_addr);
>> + while (counter) {
>> + ifx_creq = ioread32(creq_addr) & CAN_IF_CREQ_BUSY;
>> + if (!ifx_creq)
>> + break;
>> + counter--;
>> + udelay(1);
>> + }
>> + if (!counter)
>> + pr_err("%s:IF1 BUSY Flag is set forever.\n", __func__);
>> +}
>> +
>> +static void pch_can_set_int_enables(struct pch_can_priv *priv,
>> + enum pch_can_mode interrupt_no)
>> +{
>> + switch (interrupt_no) {
>> + case PCH_CAN_ENABLE:
>> + pch_can_bit_set(&priv->regs->cont, CAN_CTRL_IE);
>
> noone uses this case.
>
>> + break;
>> +
>> + case PCH_CAN_DISABLE:
>> + pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE);
>> + break;
>> +
>> + case PCH_CAN_ALL:
>> + pch_can_bit_set(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
>> + break;
>> +
>> + case PCH_CAN_NONE:
>> + pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
>> + break;
>> +
>> + default:
>> + dev_err(&priv->ndev->dev, "Invalid interrupt number.\n");
>> + break;
>> + }
>> +}
>> +
>> +static void pch_can_set_rx_enable(struct pch_can_priv *priv, u32 buff_num,
>> + int set)
>> +{
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> + /* Reading the receive buffer data from RAM to Interface1 registers */
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
>> +
>> + /* Setting the IF1MASK1 register to access MsgVal and RxIE bits */
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_ARB | CAN_CMASK_CTRL,
>> + &priv->regs->if1_cmask);
>> +
>> + if (set == 1) {
>> + /* Setting the MsgVal and RxIE bits */
>> + pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_RXIE);
>> + pch_can_bit_set(&priv->regs->if1_id2, CAN_ID_MSGVAL);
>> +
>> + } else if (set == 0) {
>> + /* Resetting the MsgVal and RxIE bits */
>> + pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_RXIE);
>> + pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID_MSGVAL);
>> + }

Why not just?

if (set)
else

>> + pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> +}
>> +
>> +static void pch_can_rx_enable_all(struct pch_can_priv *priv)
>> +{
>> + int i;
>> +
>> + /* Traversing to obtain the object configured as receivers. */
>> + for (i = 1; i <= PCH_RX_OBJ_NUM; i++)
>> + pch_can_set_rx_enable(priv, i, 1);
>> +}
>> +
>> +static void pch_can_rx_disable_all(struct pch_can_priv *priv)
>> +{
>> + int i;
>> +
>> + /* Traversing to obtain the object configured as receivers. */
>> + for (i = 1; i <= PCH_RX_OBJ_NUM; i++)
>> + pch_can_set_rx_enable(priv, i, 0);
>> +}
>> +
>> +static void pch_can_set_tx_enable(struct pch_can_priv *priv, u32 buff_num,
>> + u32 set)
>> +{
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> + /* Reading the Msg buffer from Message RAM to Interface2 registers. */
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
>> + pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
>> +
>> + /* Setting the IF2CMASK register for accessing the
>> + MsgVal and TxIE bits */
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_ARB | CAN_CMASK_CTRL,
>> + &priv->regs->if2_cmask);
>> +
>> + if (set == 1) {
>> + /* Setting the MsgVal and TxIE bits */
>> + pch_can_bit_set(&priv->regs->if2_mcont, CAN_IF_MCONT_TXIE);
>> + pch_can_bit_set(&priv->regs->if2_id2, CAN_ID_MSGVAL);
>> + } else if (set == 0) {
>> + /* Resetting the MsgVal and TxIE bits. */
>> + pch_can_bit_clear(&priv->regs->if2_mcont, CAN_IF_MCONT_TXIE);
>> + pch_can_bit_clear(&priv->regs->if2_id2, CAN_ID_MSGVAL);
>> + }
>> +
>> + pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> +}

That function is almost identical to pch_can_set_rx_enable. Just if2 is
used instead of if1 and CAN_IF_MCONT_TXIE instead of CAN_IF_MCONT_RXIE.
With separate "struct pch_can_if" for if1 and if2, it could be handled
by a common function.

>> +static void pch_can_tx_enable_all(struct pch_can_priv *priv)
>> +{
>> + int i;
>> +
>> + /* Traversing to obtain the object configured as transmit object. */
>> + for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++)
>> + pch_can_set_tx_enable(priv, i, 1);
>> +}
>> +
>> +static void pch_can_tx_disable_all(struct pch_can_priv *priv)
>> +{
>> + int i;
>> +
>> + /* Traversing to obtain the object configured as transmit object. */
>> + for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++)
>> + pch_can_set_tx_enable(priv, i, 0);
>> +}

I think there is no need for separate functions for enable and disable.
Just pass "enable" 0 or 1 like you do with "set" above.

>> +static int pch_can_int_pending(struct pch_can_priv *priv)
> ^^^
>
> make it u32 as it returns a register value, or a u16 as you only use
> the 16 lower bits.
>
>> +{
>> + return ioread32(&priv->regs->intr) & 0xffff;
>> +}
>> +
>> +static void pch_can_clear_buffers(struct pch_can_priv *priv)
>> +{
>> + int i; /* Msg Obj ID (1~32) */
>> +
>> + for (i = 1; i <= PCH_RX_OBJ_NUM; i++) {
>
> IMHO the readability would be improved if you define something like
> PCH_RX_OBJ_START and PCH_RX_OBJ_END.
>
>> + iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if1_cmask);
>> + iowrite32(0xffff, &priv->regs->if1_mask1);
>> + iowrite32(0xffff, &priv->regs->if1_mask2);
>> + iowrite32(0x0, &priv->regs->if1_id1);
>> + iowrite32(0x0, &priv->regs->if1_id2);
>> + iowrite32(0x0, &priv->regs->if1_mcont);
>> + iowrite32(0x0, &priv->regs->if1_dataa1);
>> + iowrite32(0x0, &priv->regs->if1_dataa2);
>> + iowrite32(0x0, &priv->regs->if1_datab1);
>> + iowrite32(0x0, &priv->regs->if1_datab2);
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
>> + CAN_CMASK_ARB | CAN_CMASK_CTRL,
>> + &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, i);
>> + }
>> +
>> + for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++) {
> ^^^^^^^^^^^^^^^^^^
> dito for TX objects
>
>> + iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if2_cmask);
>> + iowrite32(0xffff, &priv->regs->if2_mask1);
>> + iowrite32(0xffff, &priv->regs->if2_mask2);
>> + iowrite32(0x0, &priv->regs->if2_id1);
>> + iowrite32(0x0, &priv->regs->if2_id2);
>> + iowrite32(0x0, &priv->regs->if2_mcont);
>> + iowrite32(0x0, &priv->regs->if2_dataa1);
>> + iowrite32(0x0, &priv->regs->if2_dataa2);
>> + iowrite32(0x0, &priv->regs->if2_datab1);
>> + iowrite32(0x0, &priv->regs->if2_datab2);
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK | CAN_CMASK_ARB |
>> + CAN_CMASK_CTRL, &priv->regs->if2_cmask);
>> + pch_can_check_if_busy(&priv->regs->if2_creq, i);

This is almost the same code as above, just if2 instead of if1. With
separate "struct pch_can_if" for if1 and i2, it could be handled by a
common function.

>> + }
>> +}
>> +
>> +static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)
>> +{
>> + int i;
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> +
>> + for (i = 1; i <= PCH_RX_OBJ_NUM; i++) {
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, i);
>
> If I understand the code correctly, the about function triggers a
> transfer. Why do you first trigger a transfer, then set the message contents....
>> +
>> + iowrite32(0x0, &priv->regs->if1_id1);
>> + iowrite32(0x0, &priv->regs->if1_id2);
>> +
>> + pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_UMASK);
>
> Why do you set the "Use acceptance mask" bit? We want to receive
> all can messages.
>
>> +
>> + /* Set FIFO mode set to 0 except last Rx Obj*/
>> + pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
>> + /* In case FIFO mode, Last EoB of Rx Obj must be 1 */
>> + if (i == (PCH_RX_OBJ_NUM - 1))
>> + pch_can_bit_set(&priv->regs->if1_mcont,
>> + CAN_IF_MCONT_EOB);
>
> Make it if () { } else { }, please.
>
>> +
>> + iowrite32(0, &priv->regs->if1_mask1);
>> + pch_can_bit_clear(&priv->regs->if1_mask2,
>> + 0x1fff | CAN_MASK2_MDIR_MXTD);
>> +
>> + /* Setting CMASK for writing */
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK | CAN_CMASK_ARB |
>> + CAN_CMASK_CTRL, &priv->regs->if1_cmask);
>> +
>> + pch_can_check_if_busy(&priv->regs->if1_creq, i);
>
> ...and then trigger the transfer again?
>
>> + }
>> +
>> + for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++) {
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
>> + pch_can_check_if_busy(&priv->regs->if2_creq, i);
>
> same question about triggering the transfer 2 times applied here, too
>> +
>> + /* Resetting DIR bit for reception */
>> + iowrite32(0x0, &priv->regs->if2_id1);
>> + iowrite32(0x0, &priv->regs->if2_id2);
>> + pch_can_bit_set(&priv->regs->if2_id2, CAN_ID2_DIR);
>
> Can you combine the two accesses to >if2_id2 into one?
>
>> +
>> + /* Setting EOB bit for transmitter */
>> + iowrite32(CAN_IF_MCONT_EOB, &priv->regs->if2_mcont);
>> +
>> + pch_can_bit_set(&priv->regs->if2_mcont,
>> + CAN_IF_MCONT_UMASK);
>
> dito for if2_mcont
>
>> +
>> + iowrite32(0, &priv->regs->if2_mask1);
>> + pch_can_bit_clear(&priv->regs->if2_mask2, 0x1fff);
>> +
>> + /* Setting CMASK for writing */
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK | CAN_CMASK_ARB |
>> + CAN_CMASK_CTRL, &priv->regs->if2_cmask);
>> +
>> + pch_can_check_if_busy(&priv->regs->if2_creq, i);
>> + }
>> +
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> +}
>> +
>> +static void pch_can_init(struct pch_can_priv *priv)
>> +{
>> + /* Stopping the Can device. */
>> + pch_can_set_run_mode(priv, PCH_CAN_STOP);
>> +
>> + /* Clearing all the message object buffers. */
>> + pch_can_clear_buffers(priv);
>> +
>> + /* Configuring the respective message object as either rx/tx object. */
>> + pch_can_config_rx_tx_buffers(priv);
>> +
>> + /* Enabling the interrupts. */
>> + pch_can_set_int_enables(priv, PCH_CAN_ALL);
>> +}
>> +
>> +static void pch_can_release(struct pch_can_priv *priv)
>> +{
>> + /* Stooping the CAN device. */
>> + pch_can_set_run_mode(priv, PCH_CAN_STOP);
>> +
>> + /* Disabling the interrupts. */
>> + pch_can_set_int_enables(priv, PCH_CAN_NONE);
>> +
>> + /* Disabling all the receive object. */
>> + pch_can_rx_disable_all(priv);
>> +
>> + /* Disabling all the transmit object. */
>> + pch_can_tx_disable_all(priv);
>> +}
>> +
>> +/* This function clears interrupt(s) from the CAN device. */
>> +static void pch_can_int_clr(struct pch_can_priv *priv, u32 mask)
>> +{
>> + if (mask == CAN_STATUS_INT) {
>
> is this a valid case?
>
>> + ioread32(&priv->regs->stat);
>> + return;
>> + }
>> +
>> + /* Clear interrupt for transmit object */
>> + if ((mask >= 1) && (mask <= PCH_RX_OBJ_NUM)) {
>> + /* Setting CMASK for clearing the reception interrupts. */
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL | CAN_CMASK_ARB,
>> + &priv->regs->if1_cmask);
>> +
>> + /* Clearing the Dir bit. */
>> + pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID2_DIR);
>> +
>> + /* Clearing NewDat & IntPnd */
>> + pch_can_bit_clear(&priv->regs->if1_mcont,
>> + CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND);
>> +
>> + pch_can_check_if_busy(&priv->regs->if1_creq, mask);
>> + } else if ((mask > PCH_RX_OBJ_NUM) && (mask <= PCH_OBJ_NUM)) {
>> + /* Setting CMASK for clearing interrupts for
>> + frame transmission. */
>
> /*
> * this is the prefered style of multi line comments,
> * please adjust you comments
> */
>
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL | CAN_CMASK_ARB,
>> + &priv->regs->if2_cmask);
>> +
>> + /* Resetting the ID registers. */
>> + pch_can_bit_set(&priv->regs->if2_id2,
>> + CAN_ID2_DIR | (0x7ff << 2));
>> + iowrite32(0x0, &priv->regs->if2_id1);
>> +
>> + /* Claring NewDat, TxRqst & IntPnd */
>> + pch_can_bit_clear(&priv->regs->if2_mcont,
>> + CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND |
>> + CAN_IF_MCONT_TXRQXT);
>> + pch_can_check_if_busy(&priv->regs->if2_creq, mask);
>> + }
>> +}
>> +
>> +static u32 pch_can_get_buffer_status(struct pch_can_priv *priv)
>> +{
>> + return (ioread32(&priv->regs->treq1) & 0xffff) |
>> + ((ioread32(&priv->regs->treq2) & 0xffff) << 16);
>
> the second 0xffff is not needed, as the return value is u32 and you shift by 16.
>
>> +}
>> +
>> +static void pch_can_reset(struct pch_can_priv *priv)
>> +{
>> + /* write to sw reset register */
>> + iowrite32(1, &priv->regs->srst);
>> + iowrite32(0, &priv->regs->srst);
>> +}
>> +
>> +static void pch_can_error(struct net_device *ndev, u32 status)
>> +{
>> + struct sk_buff *skb;
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> + struct can_frame *cf;
>> + u32 errc;
>> + struct net_device_stats *stats = &(priv->ndev->stats);
>> + enum can_state state = priv->can.state;
>> +
>> + skb = alloc_can_err_skb(ndev, &cf);
>> + if (!skb)
>> + return;
>> +
>> + if (status & PCH_BUS_OFF) {
>> + pch_can_tx_disable_all(priv);
>> + pch_can_rx_disable_all(priv);
>> + state = CAN_STATE_BUS_OFF;
>> + cf->can_id |= CAN_ERR_BUSOFF;
>> + can_bus_off(ndev);
>> + }
>> +
>> + /* Warning interrupt. */
>> + if (status & PCH_EWARN) {
>> + state = CAN_STATE_ERROR_WARNING;
>> + priv->can.can_stats.error_warning++;
>> + cf->can_id |= CAN_ERR_CRTL;
>> + errc = ioread32(&priv->regs->errc);
>> + if (((errc & CAN_REC) >> 8) > 96)
>> + cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
>> + if ((errc & CAN_TEC) > 96)
>> + cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
>> + dev_warn(&ndev->dev,
>> + "%s -> Error Counter is more than 96.\n", __func__);
>
> Please use just "debug" level not warning here. Consider to use
> netdev_dbg() instead. IMHO the __func__ can be dropped and the
> "official" name for the error is "Error Warning".
>
>> + }
>> + /* Error passive interrupt. */
>> + if (status & PCH_EPASSIV) {
>> + priv->can.can_stats.error_passive++;
>> + state = CAN_STATE_ERROR_PASSIVE;
>> + cf->can_id |= CAN_ERR_CRTL;
>> + errc = ioread32(&priv->regs->errc);
>> + if (((errc & CAN_REC) >> 8) > 127)
>> + cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
>> + if ((errc & CAN_TEC) > 127)
>> + cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
>> + dev_err(&ndev->dev,
>> + "%s -> CAN controller is ERROR PASSIVE .\n", __func__);
>
> dito
>
>> + }
>> +
>> + if (status & PCH_LEC_ALL) {
>> + priv->can.can_stats.bus_error++;
>> + stats->rx_errors++;
>> + switch (status & PCH_LEC_ALL) {
>
> I suggest to convert to a if-bit-set because there might be more than
> one bit set.

Marc, what do you mean here. It's an enumeraton. Maybe the following
code is more clear:

lec = status & PCH_LEC_ALL;
if (lec > 0) {
switch (lec) {

>> + case PCH_STUF_ERR:
>> + cf->data[2] |= CAN_ERR_PROT_STUFF;
>> + break;
>> + case PCH_FORM_ERR:
>> + cf->data[2] |= CAN_ERR_PROT_FORM;
>> + break;
>> + case PCH_ACK_ERR:
>> + cf->data[2] |= CAN_ERR_PROT_LOC_ACK |
>> + CAN_ERR_PROT_LOC_ACK_DEL;

Could you check what that type of bus error that is? Usually it's a ack
lost error.

>> + break;
>> + case PCH_BIT1_ERR:
>> + case PCH_BIT0_ERR:
>> + cf->data[2] |= CAN_ERR_PROT_BIT;
>> + break;
>> + case PCH_CRC_ERR:
>> + cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ |
>> + CAN_ERR_PROT_LOC_CRC_DEL;
>> + break;
>> + default:
>> + iowrite32(status | PCH_LEC_ALL, &priv->regs->stat);
>> + break;
>> + }
>> +
>> + }

Also, could you please add the TEC and REC:

cf->data[6] = ioread32(&priv->regs->errc) & CAN_TEC;
cf->data[7] = (ioread32(&priv->regs->errc) & CAN_REC) >> 8;

>> + priv->can.state = state;
>> + netif_receive_skb(skb);
>> +
>> + stats->rx_packets++;
>> + stats->rx_bytes += cf->can_dlc;
>> +}
>> +
>> +static irqreturn_t pch_can_interrupt(int irq, void *dev_id)
>> +{
>> + struct net_device *ndev = (struct net_device *)dev_id;
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> +
>> + pch_can_set_int_enables(priv, PCH_CAN_NONE);
>> + napi_schedule(&priv->napi);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static void pch_fifo_thresh(struct pch_can_priv *priv, int obj_id)
>> +{
>> + if (obj_id < PCH_FIFO_THRESH) {
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL |
>> + CAN_CMASK_ARB, &priv->regs->if1_cmask);
>> +
>> + /* Clearing the Dir bit. */
>> + pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID2_DIR);
>> +
>> + /* Clearing NewDat & IntPnd */
>> + pch_can_bit_clear(&priv->regs->if1_mcont,
>> + CAN_IF_MCONT_INTPND);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, obj_id);
>> + } else if (obj_id > PCH_FIFO_THRESH) {
>> + pch_can_int_clr(priv, obj_id);
>> + } else if (obj_id == PCH_FIFO_THRESH) {
>> + int cnt;
>> + for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)
>> + pch_can_int_clr(priv, cnt+1);
>> + }
>> +}
>> +
>> +static int pch_can_rx_msg_lost(struct net_device *ndev, int obj_id)
>> +{
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> + struct net_device_stats *stats = &(priv->ndev->stats);
>> + struct sk_buff *skb;
>> + struct can_frame *cf;
>> +
>> + dev_err(&priv->ndev->dev, "Msg Obj is overwritten.\n");

Please use dev_dbg or even remove the line above.

>> + pch_can_bit_clear(&priv->regs->if1_mcont,
>> + CAN_IF_MCONT_MSGLOST);
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL,
>> + &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, obj_id);

I think the if busy checks could be improved. Why do you need to wait here?

>> +
>> + skb = alloc_can_err_skb(ndev, &cf);
>> + if (!skb)
>> + return -ENOMEM;
>> +
>> + priv->can.can_stats.error_passive++;
>> + priv->can.state = CAN_STATE_ERROR_PASSIVE;

Please remove the above two bogus lines.

>> + cf->can_id |= CAN_ERR_CRTL;
>> + cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
>> + stats->rx_over_errors++;
>> + stats->rx_errors++;
>> +
>> + netif_receive_skb(skb);
>> +
>> + return 0;
>> +}
>> +
>> +static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota)
>> +{
>> + u32 reg;
>> + canid_t id;
>> + u32 ide;
>> + u32 rtr;
>> + int rcv_pkts = 0;
>> + int rtn;
>> + int next_flag = 0;
>> + struct sk_buff *skb;
>> + struct can_frame *cf;
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> + struct net_device_stats *stats = &(priv->ndev->stats);
>> +
>> + /* Reading the messsage object from the Message RAM */
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, obj_num);
>> +
>> + /* Reading the MCONT register. */
>> + reg = ioread32(&priv->regs->if1_mcont);
>> + reg &= 0xffff;
>> +
>> + for (; (!(reg & CAN_IF_MCONT_EOB)) && (quota > 0);
>> + obj_num++, next_flag = 0) {
>> + /* If MsgLost bit set. */
>> + if (reg & CAN_IF_MCONT_MSGLOST) {
>> + rtn = pch_can_rx_msg_lost(ndev, obj_num);
>> + if (!rtn)
>> + return rtn;
>> + rcv_pkts++;
>> + quota--;
>> + next_flag = 1;
>> + } else if (!(reg & CAN_IF_MCONT_NEWDAT))
>> + next_flag = 1;
>> +
>
> after rearanging the code (see below..) you should be able to use a continue here.
>
>> + if (!next_flag) {
>> + skb = alloc_can_skb(priv->ndev, &cf);
>> + if (!skb)
>> + return -ENOMEM;
>> +
>> + /* Get Received data */
>> + ide = ((ioread32(&priv->regs->if1_id2)) & CAN_ID2_XTD);
>> + if (ide) {
>> + id = (ioread32(&priv->regs->if1_id1) & 0xffff);
>> + id |= (((ioread32(&priv->regs->if1_id2)) &
>> + 0x1fff) << 16);
>> + cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
> ^^^^^^^^^^^^^^^^^
>
> is the mask needed, you mask the if1_id{1,2} already
>
>> + } else {
>> + id = (((ioread32(&priv->regs->if1_id2)) &
>> + (CAN_SFF_MASK << 2)) >> 2);
>> + cf->can_id = (id & CAN_SFF_MASK);
>
> one mask can go away
>
>> + }
>> +
>> + rtr = ioread32(&priv->regs->if1_id2) & CAN_ID2_DIR;
> ^^
>
> remove one space
>
>> +
>> + if (rtr)
>> + cf->can_id |= CAN_RTR_FLAG;
>> +
>> + cf->can_dlc = get_can_dlc((ioread32(&priv->regs->
>> + if1_mcont)) & 0xF);
>> + *(u16 *)(cf->data + 0) = ioread16(&priv->regs->
>> + if1_dataa1);
>> + *(u16 *)(cf->data + 2) = ioread16(&priv->regs->
>> + if1_dataa2);
>> + *(u16 *)(cf->data + 4) = ioread16(&priv->regs->
>> + if1_datab1);
>> + *(u16 *)(cf->data + 6) = ioread16(&priv->regs->
>> + if1_datab2);
>
> are you sure, the bytes in the can package a in the correct order.
> Please test your pch_can against a non pch_can system.
>
>> +
>> + netif_receive_skb(skb);
>> + rcv_pkts++;
>> + stats->rx_packets++;
>> + quota--;
>> + stats->rx_bytes += cf->can_dlc;
>> +
>> + pch_fifo_thresh(priv, obj_num);
>> + }
>> +
>> + /* Reading the messsage object from the Message RAM */
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, obj_num + 1);
>> + reg = ioread32(&priv->regs->if1_mcont);
>
> this is almost the same code as before the the loop, can you rearange
> the code to avoid duplication?
>
>> + }
>> +
>> + return rcv_pkts;
>> +}
>> +
>> +static void pch_can_tx_complete(struct net_device *ndev, u32 int_stat)
>> +{
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> + struct net_device_stats *stats = &(priv->ndev->stats);
>> + unsigned long flags;
>> + u32 dlc;
>> +
>> + can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_NUM - 1);
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> + iowrite32(CAN_CMASK_RX_TX_GET | CAN_CMASK_CLRINTPND,
>> + &priv->regs->if2_cmask);
>> + dlc = ioread32(&priv->regs->if2_mcont) & CAN_IF_MCONT_DLC;
>> + pch_can_check_if_busy(&priv->regs->if2_creq, int_stat);
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> + if (dlc > 8)
>> + dlc = 8;
>
> use get_can_dlc
>
>> + stats->tx_bytes += dlc;
>> + stats->tx_packets++;
>> +}
>> +
>> +static int pch_can_rx_poll(struct napi_struct *napi, int quota)
>> +{
>> + struct net_device *ndev = napi->dev;
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> + u32 int_stat;
>> + int rcv_pkts = 0;
>> + u32 reg_stat;
>> + unsigned long flags;
>> +
>> + int_stat = pch_can_int_pending(priv);
>> + if (!int_stat)
>> + goto END;

Labels should be lowercase as well.

>> +
>> + if ((int_stat == CAN_STATUS_INT) && (quota > 0)) {
>> + reg_stat = ioread32(&priv->regs->stat);
>> + if (reg_stat & (PCH_BUS_OFF | PCH_LEC_ALL)) {
>> + if ((reg_stat & PCH_LEC_ALL) != PCH_LEC_ALL) {
>> + pch_can_error(ndev, reg_stat);
>> + quota--;
>> + }
>> + }
>> +
>> + if (reg_stat & PCH_TX_OK) {
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
>> + pch_can_check_if_busy(&priv->regs->if2_creq,
>> + ioread32(&priv->regs->intr));
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> Isn't this "int_stat". Might it be possilbe that regs->intr changes
> between the pch_can_int_pending and here?
>
> What should this transfer do?
>
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> + pch_can_bit_clear(&priv->regs->stat, PCH_TX_OK);
>> + }
>> +
>> + if (reg_stat & PCH_RX_OK)
>> + pch_can_bit_clear(&priv->regs->stat, PCH_RX_OK);
>> +
>> + int_stat = pch_can_int_pending(priv);
>> + }
>> +
>> + if (quota == 0)
>> + goto END;
>> +
>> + if ((int_stat >= 1) && (int_stat <= PCH_RX_OBJ_NUM)) {
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> + rcv_pkts += pch_can_rx_normal(ndev, int_stat, quota);
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> + quota -= rcv_pkts;
>> + if (rcv_pkts < 0)
>
> how can this happen?
>
>> + goto END;
>> + } else if ((int_stat > PCH_RX_OBJ_NUM) && (int_stat <= PCH_OBJ_NUM)) {
>> + /* Handle transmission interrupt */
>> + pch_can_tx_complete(ndev, int_stat);
>> + }
>> +
>> +END:
>> + napi_complete(napi);
>> + pch_can_set_int_enables(priv, PCH_CAN_ALL);
>> +
>> + return rcv_pkts;
>> +}
>> +
>> +static int pch_set_bittiming(struct net_device *ndev)
>> +{
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> + const struct can_bittiming *bt = &priv->can.bittiming;
>> + u32 canbit;
>> + u32 bepe;
>> +
>> + /* Setting the CCE bit for accessing the Can Timing register. */
>> + pch_can_bit_set(&priv->regs->cont, CAN_CTRL_CCE);
>> +
>> + canbit = (bt->brp - 1) & MSK_BITT_BRP;
>> + canbit |= (bt->sjw - 1) << BIT_BITT_SJW;
>> + canbit |= (bt->phase_seg1 + bt->prop_seg - 1) << BIT_BITT_TSEG1;
>> + canbit |= (bt->phase_seg2 - 1) << BIT_BITT_TSEG2;
>> + bepe = ((bt->brp - 1) & MSK_BRPE_BRPE) >> BIT_BRPE_BRPE;
>> + iowrite32(canbit, &priv->regs->bitt);
>> + iowrite32(bepe, &priv->regs->brpe);
>> + pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_CCE);
>> +
>> + return 0;
>> +}
>> +
>> +static void pch_can_start(struct net_device *ndev)
>> +{
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> +
>> + if (priv->can.state != CAN_STATE_STOPPED)
>> + pch_can_reset(priv);
>> +
>> + pch_set_bittiming(ndev);
>> + pch_can_set_optmode(priv);
>> +
>> + pch_can_tx_enable_all(priv);
>> + pch_can_rx_enable_all(priv);
>> +
>> + /* Setting the CAN to run mode. */
>> + pch_can_set_run_mode(priv, PCH_CAN_RUN);
>> +
>> + priv->can.state = CAN_STATE_ERROR_ACTIVE;
>> +
>> + return;
>> +}
>> +
>> +static int pch_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
>> +{
>> + int ret = 0;
>> +
>> + switch (mode) {
>> + case CAN_MODE_START:
>> + pch_can_start(ndev);
>> + netif_wake_queue(ndev);
>> + break;
>> + default:
>> + ret = -EOPNOTSUPP;
>> + break;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int pch_can_open(struct net_device *ndev)
>> +{
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> + int retval;
>> +
>> + /* Regsitering the interrupt. */

Typo!

>> + retval = request_irq(priv->dev->irq, pch_can_interrupt, IRQF_SHARED,
>> + ndev->name, ndev);
>> + if (retval) {
>> + dev_err(&ndev->dev, "request_irq failed.\n");
>> + goto req_irq_err;
>> + }
>> +
>> + /* Open common can device */
>> + retval = open_candev(ndev);
>> + if (retval) {
>> + dev_err(ndev->dev.parent, "open_candev() failed %d\n", retval);
>> + goto err_open_candev;
>> + }
>> +
>> + pch_can_init(priv);
>> + pch_can_start(ndev);
>> + napi_enable(&priv->napi);
>> + netif_start_queue(ndev);
>> +
>> + return 0;
>> +
>> +err_open_candev:
>> + free_irq(priv->dev->irq, ndev);
>> +req_irq_err:
>> + pch_can_release(priv);
>> +
>> + return retval;
>> +}
>> +
>> +static int pch_close(struct net_device *ndev)
>> +{
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> +
>> + netif_stop_queue(ndev);
>> + napi_disable(&priv->napi);
>> + pch_can_release(priv);
>> + free_irq(priv->dev->irq, ndev);
>> + close_candev(ndev);
>> + priv->can.state = CAN_STATE_STOPPED;
>> + return 0;
>> +}
>> +
>> +static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
>> +{
>> + unsigned long flags;
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> + struct can_frame *cf = (struct can_frame *)skb->data;
>> + int tx_buffer_avail = 0;
>
> What I'm totally missing is the TX flow controll. Your driver has to
> ensure that the package leave the controller in the order that come
> into the xmit function. Further you have to stop your xmit queue if
> you're out of tx objects and reenable if you have a object free.
>
> Use netif_stop_queue() and netif_wake_queue() for this.
>
>> +
>> + if (can_dropped_invalid_skb(ndev, skb))
>> + return NETDEV_TX_OK;
>> +
>> + if (priv->tx_obj == (PCH_OBJ_NUM + 1)) { /* Point tail Obj + 1 */
>> + while (ioread32(&priv->regs->treq2) & 0xfc00)
>> + udelay(1);
>
> please no (possible) infinite delays!
>
>> + priv->tx_obj = PCH_RX_OBJ_NUM + 1; /* Point head of Tx Obj ID */
>> + }
>
>> +
>> + tx_buffer_avail = priv->tx_obj;
>
> why has the "object" become a "buffer" now? :)
>
>> + priv->tx_obj++;
>> +
>> + /* Attaining the lock. */
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> +
>> + /* Setting the CMASK register to set value*/
> ^^^
>
> pleas add a whitespace
>
>> + iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if2_cmask);
>> +
>> + /* If ID extended is set. */
>> + if (cf->can_id & CAN_EFF_FLAG) {
>> + iowrite32(cf->can_id & 0xffff, &priv->regs->if2_id1);
>> + iowrite32(((cf->can_id >> 16) & 0x1fff) | CAN_ID2_XTD,
>> + &priv->regs->if2_id2);
>> + } else {
>> + iowrite32(0, &priv->regs->if2_id1);
>> + iowrite32((cf->can_id & CAN_SFF_MASK) << 2,
>> + &priv->regs->if2_id2);
>> + }
>> +
>> + pch_can_bit_set(&priv->regs->if2_id2, CAN_ID_MSGVAL);
>
> Do you need to do a read-modify-write of the hardware register? Please
> prepare the values you want to write to hardware, then do it.
>
>> +
>> + /* If remote frame has to be transmitted.. */
>> + if (!(cf->can_id & CAN_RTR_FLAG))
>> + pch_can_bit_set(&priv->regs->if2_id2, CAN_ID2_DIR);
> dito
>> + /* If remote frame has to be transmitted.. */
>> + if (cf->can_id & CAN_RTR_FLAG)
>> + pch_can_bit_clear(&priv->regs->if2_id2, CAN_ID2_DIR);
> dito
>> +
>> + /* Copy data to register */
>> + if (cf->can_dlc > 0) {
>> + u32 data1 = *((u16 *)&cf->data[0]);
>> + iowrite32(data1, &priv->regs->if2_dataa1);
>
> do you think you send the bytes in correct order?
>
>> + }
>> + if (cf->can_dlc > 2) {
>> + u32 data1 = *((u16 *)&cf->data[2]);
>> + iowrite32(data1, &priv->regs->if2_dataa2);
>> + }
>> + if (cf->can_dlc > 4) {
>> + u32 data1 = *((u16 *)&cf->data[4]);
>> + iowrite32(data1, &priv->regs->if2_datab1);
>> + }
>> + if (cf->can_dlc > 6) {
>> + u32 data1 = *((u16 *)&cf->data[6]);
>> + iowrite32(data1, &priv->regs->if2_datab2);
>> + }

Could be handled by a loop.

>> + can_put_echo_skb(skb, ndev, tx_buffer_avail - PCH_RX_OBJ_NUM - 1);
>> +
>> + /* Set the size of the data. */
>> + iowrite32(cf->can_dlc, &priv->regs->if2_mcont);
>> +
>> + /* Update if2_mcont */
>> + pch_can_bit_set(&priv->regs->if2_mcont,
>> + CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_TXRQXT |
>> + CAN_IF_MCONT_TXIE);
>
> pleae first perpare your value, then write to hardware.
>
>> +
>> + if (tx_buffer_avail == PCH_RX_OBJ_NUM) /* If points tail of FIFO */
>> + pch_can_bit_set(&priv->regs->if2_mcont, CAN_IF_MCONT_EOB);
>
> dito
>
> Is EOB relevant for TX objects?
>
>> + pch_can_check_if_busy(&priv->regs->if2_creq, tx_buffer_avail);
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> +
>> + return NETDEV_TX_OK;
>> +}
>> +
>> +static const struct net_device_ops pch_can_netdev_ops = {
>> + .ndo_open = pch_can_open,
>> + .ndo_stop = pch_close,
>> + .ndo_start_xmit = pch_xmit,
>> +};
>> +
>> +static void __devexit pch_can_remove(struct pci_dev *pdev)
>> +{
>> + struct net_device *ndev = pci_get_drvdata(pdev);
>> + struct pch_can_priv *priv = netdev_priv(ndev);
>> +
>> + unregister_candev(priv->ndev);
>> + pci_iounmap(pdev, priv->regs);
>> + if (priv->use_msi)
>> + pci_disable_msi(priv->dev);
>> + pci_release_regions(pdev);
>> + pci_disable_device(pdev);
>> + pci_set_drvdata(pdev, NULL);
>> + free_candev(priv->ndev);
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +static void pch_can_set_int_custom(struct pch_can_priv *priv)
>> +{
>> + /* Clearing the IE, SIE and EIE bits of Can control register. */
>> + pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
>> +
>> + /* Appropriately setting them. */
>> + pch_can_bit_set(&priv->regs->cont,
>> + ((priv->int_enables & MSK_CTRL_IE_SIE_EIE) << 1));
>> +}
>> +
>> +/* This function retrieves interrupt enabled for the CAN device. */
>> +static u32 pch_can_get_int_enables(struct pch_can_priv *priv)
>> +{
>> + /* Obtaining the status of IE, SIE and EIE interrupt bits. */
>> + return (ioread32(&priv->regs->cont) & CAN_CTRL_IE_SIE_EIE) >> 1;
>> +}
>> +
>> +static u32 pch_can_get_rx_enable(struct pch_can_priv *priv, u32 buff_num)
>> +{
>> + unsigned long flags;
>> + u32 enable;
>> +
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
>> +
>> + if (((ioread32(&priv->regs->if1_id2)) & CAN_ID_MSGVAL) &&
>> + ((ioread32(&priv->regs->if1_mcont)) &
>> + CAN_IF_MCONT_RXIE))
>> + enable = 1;
>> + else
>> + enable = 0;
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> + return enable;
>> +}
>> +
>> +static u32 pch_can_get_tx_enable(struct pch_can_priv *priv, u32 buff_num)
>> +{
>> + unsigned long flags;
>> + u32 enable;
>> +
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> +
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
>> + pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
>> + if (((ioread32(&priv->regs->if2_id2)) & CAN_ID_MSGVAL) &&
>> + ((ioread32(&priv->regs->if2_mcont)) &
>> + CAN_IF_MCONT_TXIE)) {
>> + enable = 1;
>> + } else {
>> + enable = 0;
>> + }
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> +
>> + return enable;
>> +}

The above two functions could be handled by a common one passing "struct
pch_can_if". See similar comments above.

>> +static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
>> + u32 buffer_num, u32 set)
>> +{
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
>> + iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL, &priv->regs->if1_cmask);
>> + if (set == 1)
>> + pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
>> + else
>> + pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
>> +
>> + pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> +}
>> +
>> +static u32 pch_can_get_rx_buffer_link(struct pch_can_priv *priv, u32 buffer_num)
>> +{
>> + unsigned long flags;
>> + u32 link;
>> +
>> + spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>> + iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>> + pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
>> +
>> + if (ioread32(&priv->regs->if1_mcont) & CAN_IF_MCONT_EOB)
>> + link = 0;
>> + else
>> + link = 1;
>> + spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> + return link;
>> +}
>> +
>> +static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
>> +{
>> + int i;
>> + int retval;
>> + u32 buf_stat; /* Variable for reading the transmit buffer status. */
>> + u32 counter = COUNTER_LIMIT;
>> +
>> + struct net_device *dev = pci_get_drvdata(pdev);
>> + struct pch_can_priv *priv = netdev_priv(dev);
>> +
>> + /* Stop the CAN controller */
>> + pch_can_set_run_mode(priv, PCH_CAN_STOP);
>> +
>> + /* Indicate that we are aboutto/in suspend */
>> + priv->can.state = CAN_STATE_STOPPED;
>> +
>> + /* Waiting for all transmission to complete. */
>> + while (counter) {
>> + buf_stat = pch_can_get_buffer_status(priv);
>> + if (!buf_stat)
>> + break;
>> + counter--;
>> + udelay(1);
>> + }
>> + if (!counter)
>> + dev_err(&pdev->dev, "%s -> Transmission time out.\n", __func__);
>> +
>> + /* Save interrupt configuration and then disable them */
>> + priv->int_enables = pch_can_get_int_enables(priv);
>> + pch_can_set_int_enables(priv, PCH_CAN_DISABLE);
>> +
>> + /* Save Tx buffer enable state */
>> + for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++)
>> + priv->tx_enable[i] = pch_can_get_tx_enable(priv, i);
>> +
>> + /* Disable all Transmit buffers */
>> + pch_can_tx_disable_all(priv);
>> +
>> + /* Save Rx buffer enable state */
>> + for (i = 1; i <= PCH_RX_OBJ_NUM; i++) {
>> + priv->rx_enable[i] = pch_can_get_rx_enable(priv, i);
>> + priv->rx_link[i] = pch_can_get_rx_buffer_link(priv, i);
>> + }
>> +
>> + /* Disable all Receive buffers */
>> + pch_can_rx_disable_all(priv);
>> + retval = pci_save_state(pdev);
>> + if (retval) {
>> + dev_err(&pdev->dev, "pci_save_state failed.\n");
>> + } else {
>> + pci_enable_wake(pdev, PCI_D3hot, 0);
>> + pci_disable_device(pdev);
>> + pci_set_power_state(pdev, pci_choose_state(pdev, state));
>> + }
>> +
>> + return retval;
>> +}
>> +
>> +static int pch_can_resume(struct pci_dev *pdev)
>> +{
>> + int i;
>> + int retval;
>> + struct net_device *dev = pci_get_drvdata(pdev);
>> + struct pch_can_priv *priv = netdev_priv(dev);
>> +
>> + pci_set_power_state(pdev, PCI_D0);
>> + pci_restore_state(pdev);
>> + retval = pci_enable_device(pdev);
>> + if (retval) {
>> + dev_err(&pdev->dev, "pci_enable_device failed.\n");
>> + return retval;
>> + }
>> +
>> + pci_enable_wake(pdev, PCI_D3hot, 0);
>> +
>> + priv->can.state = CAN_STATE_ERROR_ACTIVE;
>> +
>> + /* Disabling all interrupts. */
>> + pch_can_set_int_enables(priv, PCH_CAN_DISABLE);
>> +
>> + /* Setting the CAN device in Stop Mode. */
>> + pch_can_set_run_mode(priv, PCH_CAN_STOP);
>> +
>> + /* Configuring the transmit and receive buffers. */
>> + pch_can_config_rx_tx_buffers(priv);
>> +
>> + /* Restore the CAN state */
>> + pch_set_bittiming(dev);
>> +
>> + /* Listen/Active */
>> + pch_can_set_optmode(priv);
>> +
>> + /* Enabling the transmit buffer. */
>> + for (i = 1; i <= PCH_RX_OBJ_NUM; i++)
>> + pch_can_set_tx_enable(priv, i, priv->tx_enable[i]);
>> +
>> + /* Configuring the receive buffer and enabling them. */
>> + for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++) {
>> + /* Restore buffer link */
>> + pch_can_set_rx_buffer_link(priv, i, priv->rx_link[i]);
>> +
>> + /* Restore buffer enables */
>> + pch_can_set_rx_enable(priv, i, priv->rx_enable[i]);
>> + }
>> +
>> + /* Enable CAN Interrupts */
>> + pch_can_set_int_custom(priv);
>> +
>> + /* Restore Run Mode */
>> + pch_can_set_run_mode(priv, PCH_CAN_RUN);
>> +
>> + return retval;
>> +}
>> +#else
>> +#define pch_can_suspend NULL
>> +#define pch_can_resume NULL
>> +#endif
>> +
>> +static int pch_can_get_berr_counter(const struct net_device *dev,
>> + struct can_berr_counter *bec)
>> +{
>> + struct pch_can_priv *priv = netdev_priv(dev);
>> +
>> + bec->txerr = ioread32(&priv->regs->errc) & CAN_TEC;
>> + bec->rxerr = (ioread32(&priv->regs->errc) & CAN_REC) >> 8;
>> +
>> + return 0;
>> +}
>> +
>> +static int __devinit pch_can_probe(struct pci_dev *pdev,
>> + const struct pci_device_id *id)
>> +{
>> + struct net_device *ndev;
>> + struct pch_can_priv *priv;
>> + int rc;
>> + void __iomem *addr;
>> +
>> + rc = pci_enable_device(pdev);
>> + if (rc) {
>> + dev_err(&pdev->dev, "Failed pci_enable_device %d\n", rc);
>> + goto probe_exit_endev;
>> + }
>> +
>> + rc = pci_request_regions(pdev, KBUILD_MODNAME);
>> + if (rc) {
>> + dev_err(&pdev->dev, "Failed pci_request_regions %d\n", rc);
>> + goto probe_exit_pcireq;
>> + }
>> +
>> + addr = pci_iomap(pdev, 1, 0);
>> + if (!addr) {
>> + rc = -EIO;
>> + dev_err(&pdev->dev, "Failed pci_iomap\n");
>> + goto probe_exit_ipmap;
>> + }
>> +
>> + ndev = alloc_candev(sizeof(struct pch_can_priv), PCH_TX_OBJ_NUM);
>> + if (!ndev) {
>> + rc = -ENOMEM;
>> + dev_err(&pdev->dev, "Failed alloc_candev\n");
>> + goto probe_exit_alloc_candev;
>> + }
>> +
>> + priv = netdev_priv(ndev);
>> + priv->ndev = ndev;
>> + priv->regs = addr;
>> + priv->dev = pdev;
>> + priv->can.bittiming_const = &pch_can_bittiming_const;
>> + priv->can.do_set_mode = pch_can_do_set_mode;
>> + priv->can.do_get_berr_counter = pch_can_get_berr_counter;
>> + priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
>> + CAN_CTRLMODE_LOOPBACK;

I'm missing CAN_CTRLMODE_3_SAMPLES here?

>> + priv->tx_obj = PCH_RX_OBJ_NUM + 1; /* Point head of Tx Obj */
>> +
>> + ndev->irq = pdev->irq;
>> + ndev->flags |= IFF_ECHO;
>> +
>> + pci_set_drvdata(pdev, ndev);
>> + SET_NETDEV_DEV(ndev, &pdev->dev);
>> + ndev->netdev_ops = &pch_can_netdev_ops;
>> + priv->can.clock.freq = PCH_CAN_CLK; /* Hz */
>> +
>> + netif_napi_add(ndev, &priv->napi, pch_can_rx_poll, PCH_RX_OBJ_NUM);
>> +
>> + rc = pci_enable_msi(priv->dev);
>> + if (rc) {
>> + dev_info(&ndev->dev, "PCH CAN opened without MSI\n");
>> + priv->use_msi = 0;
>> + } else {
>> + dev_info(&ndev->dev, "PCH CAN opened with MSI\n");
>> + priv->use_msi = 1;
>> + }
>> +
>> + rc = register_candev(ndev);
>> + if (rc) {
>> + dev_err(&pdev->dev, "Failed register_candev %d\n", rc);
>> + goto probe_exit_reg_candev;
>> + }
>> +
>> + return 0;
>> +
>> +probe_exit_reg_candev:
>> + free_candev(ndev);
>> +probe_exit_alloc_candev:
>> + pci_iounmap(pdev, addr);
>> +probe_exit_ipmap:
>> + pci_release_regions(pdev);
>> +probe_exit_pcireq:
>> + pci_disable_device(pdev);
>> +probe_exit_endev:
>> + return rc;
>> +}
>> +
>> +static struct pci_driver pch_can_pcidev = {
>> + .name = "pch_can",
>> + .id_table = pch_pci_tbl,
>> + .probe = pch_can_probe,
>> + .remove = __devexit_p(pch_can_remove),
>> + .suspend = pch_can_suspend,
>> + .resume = pch_can_resume,
>> +};
>> +
>> +static int __init pch_can_pci_init(void)
>> +{
>> + return pci_register_driver(&pch_can_pcidev);
>> +}
>> +module_init(pch_can_pci_init);
>> +
>> +static void __exit pch_can_pci_exit(void)
>> +{
>> + pci_unregister_driver(&pch_can_pcidev);
>> +}
>> +module_exit(pch_can_pci_exit);
>> +
>> +MODULE_DESCRIPTION("Intel EG20T PCH CAN(Controller Area Network) Driver");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_VERSION("0.94");

As the driver has already been merged. Please provide incremental
patches against the net-2.6 branch. Also, it would be nice if you could
check in-order transmission and reception, e.g., with the can-utils
program canfdtest:

http://svn.berlios.de/wsvn/socketcan/trunk/can-utils/canfdtest.c

Thanks,

Wolfgang.