On 9/29/20 10:30 PM, Joakim Zhang wrote: > One issue was reported at a baremetal environment, which is used for > FPGA verification. "The first transfer will fail for extended ID > format(for both 2.0B and FD format), following frames can be transmitted > and received successfully for extended format, and standard format don't > have this issue. This issue occurred randomly with high possiblity, when > it occurs, the transmitter will detect a BIT1 error, the receiver a CRC > error. According to the spec, a non-correctable error may cause this > transfer failure." > > With FLEXCAN_QUIRK_DISABLE_MECR quirk, it supports correctable errors, > disable non-correctable errors interrupt and freeze mode. Platform has > ECC hardware support, but select this quirk, this issue may not come to > light. Initialize all FlexCAN memory before accessing them, at least it > can avoid non-correctable errors detected due to memory uninitialized. > The internal region can't be initialized when the hardware doesn't support > ECC. > > According to IMX8MPRM, Rev.C, 04/2020. There is a NOTE at the section > 11.8.3.13 Detection and correction of memory errors: > "All FlexCAN memory must be initialized before starting its operation in > order to have the parity bits in memory properly updated. 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." > > Memory range from 0x080 to 0xADF, there are reserved memory (unimplemented > by hardware, e.g. only configure 64 MBs), these memory can be initialized or not. > In this patch, initialize all flexcan memory which includes reserved memory. > > In this patch, create FLEXCAN_QUIRK_SUPPORT_ECC for platforms which has ECC > feature. If you have a ECC platform in your hand, please select this > qurik to initialize all flexcan memory firstly, then you can select > FLEXCAN_QUIRK_DISABLE_MECR to only enable correctable errors. > > Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx> > --- > ChangeLogs: > V1->V2: > * update commit messages, add a datasheet reference. > * initialize block memory instead of trivial memory. > * inilialize reserved memory. > V2->V3: > * add FLEXCAN_QUIRK_SUPPORT_ECC quirk. > * remove init_ram struct. > V3->V4: > * move register definition into flexcan_reg. > --- > drivers/net/can/flexcan.c | 51 +++++++++++++++++++++++++++++++++++++-- > 1 file changed, 49 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c > index e86925134009..ede25db42e87 100644 > --- a/drivers/net/can/flexcan.c > +++ b/drivers/net/can/flexcan.c > @@ -239,6 +239,8 @@ > #define FLEXCAN_QUIRK_SETUP_STOP_MODE BIT(8) > /* Support CAN-FD mode */ > #define FLEXCAN_QUIRK_SUPPORT_FD BIT(9) > +/* support memory detection and correction */ > +#define FLEXCAN_QUIRK_SUPPORT_ECC BIT(10) > > /* Structure of the message buffer */ > struct flexcan_mb { > @@ -292,7 +294,16 @@ struct flexcan_regs { > u32 rximr[64]; /* 0x880 - Not affected by Soft Reset */ > u32 _reserved5[24]; /* 0x980 */ > u32 gfwr_mx6; /* 0x9e0 - MX6 */ > - u32 _reserved6[63]; /* 0x9e4 */ > + u32 _reserved6[39]; /* 0x9e4 */ > + u32 _rxfir[6]; /* 0xa80 */ > + u32 _reserved8[2]; /* 0xa98 */ > + u32 _rxmgmask; /* 0xaa0 */ > + u32 _rxfgmask; /* 0xaa4 */ > + u32 _rx14mask; /* 0xaa8 */ > + u32 _rx15mask; /* 0xaac */ > + u32 tx_smb[4]; /* 0xab0 */ > + u32 rx_smb0[4]; /* 0xac0 */ > + u32 rx_smb1[4]; /* 0xad0 */ > u32 mecr; /* 0xae0 */ > u32 erriar; /* 0xae4 */ > u32 erridpr; /* 0xae8 */ > @@ -305,9 +316,13 @@ struct flexcan_regs { > u32 fdctrl; /* 0xc00 - Not affected by Soft Reset */ > u32 fdcbt; /* 0xc04 - Not affected by Soft Reset */ > u32 fdcrc; /* 0xc08 */ > + u32 _reserved9[199]; /* 0xc0c */ > + u32 tx_smb_fd[18]; /* 0xf28 */ > + u32 rx_smb0_fd[18]; /* 0xf70 */ > + u32 rx_smb1_fd[18]; /* 0xfb8 */ > }; > > -static_assert(sizeof(struct flexcan_regs) == 0x4 + 0xc08); > +static_assert(sizeof(struct flexcan_regs) == 0x4 * 18 + 0xfb8); > > struct flexcan_devtype_data { > u32 quirks; /* quirks needed for different IP cores */ > @@ -1292,6 +1307,35 @@ static void flexcan_set_bittiming(struct net_device *dev) > 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(®s->ctrl2); > + reg_ctrl2 |= FLEXCAN_CTRL2_WRMFRZ; > + priv->write(reg_ctrl2, ®s->ctrl2); > + > + memset_io(®s->mb[0][0], 0, > + (u8 *)®s->rx_smb1[3] - ®s->mb[0][0] + 0x4); why the cast? > + > + if (priv->can.ctrlmode & CAN_CTRLMODE_FD) > + memset_io(®s->tx_smb_fd[0], 0, > + (u8 *)®s->rx_smb1_fd[17] - (u8 *)®s->tx_smb_fd[0] + 0x4); why the cast? > + > + reg_ctrl2 &= ~FLEXCAN_CTRL2_WRMFRZ; > + priv->write(reg_ctrl2, ®s->ctrl2); > +} > + > /* flexcan_chip_start > * > * this functions is entered with clocks enabled > @@ -1316,6 +1360,9 @@ static int flexcan_chip_start(struct net_device *dev) > if (err) > goto out_chip_disable; > > + if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_ECC) > + flexcan_init_ram(dev); > + > flexcan_set_bittiming(dev); > > /* MCR > Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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