From: Jarkko Nikula jarkko.nikula@linux.intel.com

This reverts commit 0e8ffdf3b86dfd44b651f91b12fcae76c25c453b.

Commit 0e8ffdf3b86d ("can: m_can: pci: use custom bit timings for Elkhart Lake") broke the test case using bitrate switching.

| ip link set can0 up type can bitrate 500000 dbitrate 4000000 fd on | ip link set can1 up type can bitrate 500000 dbitrate 4000000 fd on | candump can0 & | cangen can1 -I 0x800 -L 64 -e -fb \ | -D 11223344deadbeef55667788feedf00daabbccdd44332211 -n 1 -v -v

Above commit does everything correctly according to the datasheet. However datasheet wasn't correct.

I got confirmation from hardware engineers that the actual CAN hardware on Intel Elkhart Lake is based on M_CAN version v3.2.0. Datasheet was mirroring values from an another specification which was based on earlier M_CAN version leading to wrong bit timings.

Therefore revert the commit and switch back to common bit timings.

Fixes: 0e8ffdf3b86d ("can: m_can: pci: use custom bit timings for Elkhart Lake") Link: https://lore.kernel.org/all/20220512124144.536850-1-jarkko.nikula@linux.inte... Signed-off-by: Jarkko Nikula jarkko.nikula@linux.intel.com Reported-by: Chee Hou Ong chee.houx.ong@intel.com Reported-by: Aman Kumar aman.kumar@intel.com Reported-by: Pallavi Kumari kumari.pallavi@intel.com Cc: stable@vger.kernel.org # v5.16+ Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- drivers/net/can/m_can/m_can_pci.c | 48 +++---------------------------- 1 file changed, 4 insertions(+), 44 deletions(-)

diff --git a/drivers/net/can/m_can/m_can_pci.c b/drivers/net/can/m_can/m_can_pci.c index b56a54d6c5a9..8f184a852a0a 100644 --- a/drivers/net/can/m_can/m_can_pci.c +++ b/drivers/net/can/m_can/m_can_pci.c @@ -18,14 +18,9 @@

#define M_CAN_PCI_MMIO_BAR 0

+#define M_CAN_CLOCK_FREQ_EHL 200000000 #define CTL_CSR_INT_CTL_OFFSET 0x508

-struct m_can_pci_config { - const struct can_bittiming_const *bit_timing; - const struct can_bittiming_const *data_timing; - unsigned int clock_freq; -}; - struct m_can_pci_priv { struct m_can_classdev cdev;

@@ -89,40 +84,9 @@ static struct m_can_ops m_can_pci_ops = { .read_fifo = iomap_read_fifo, };

-static const struct can_bittiming_const m_can_bittiming_const_ehl = { - .name = KBUILD_MODNAME, - .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */ - .tseg1_max = 64, - .tseg2_min = 1, /* Time segment 2 = phase_seg2 */ - .tseg2_max = 128, - .sjw_max = 128, - .brp_min = 1, - .brp_max = 512, - .brp_inc = 1, -}; - -static const struct can_bittiming_const m_can_data_bittiming_const_ehl = { - .name = KBUILD_MODNAME, - .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */ - .tseg1_max = 16, - .tseg2_min = 1, /* Time segment 2 = phase_seg2 */ - .tseg2_max = 8, - .sjw_max = 4, - .brp_min = 1, - .brp_max = 32, - .brp_inc = 1, -}; - -static const struct m_can_pci_config m_can_pci_ehl = { - .bit_timing = &m_can_bittiming_const_ehl, - .data_timing = &m_can_data_bittiming_const_ehl, - .clock_freq = 200000000, -}; - static int m_can_pci_probe(struct pci_dev *pci, const struct pci_device_id *id) { struct device *dev = &pci->dev; - const struct m_can_pci_config *cfg; struct m_can_classdev *mcan_class; struct m_can_pci_priv *priv; void __iomem *base; @@ -150,8 +114,6 @@ static int m_can_pci_probe(struct pci_dev *pci, const struct pci_device_id *id) if (!mcan_class) return -ENOMEM;

- cfg = (const struct m_can_pci_config *)id->driver_data; - priv = cdev_to_priv(mcan_class);

priv->base = base; @@ -163,9 +125,7 @@ static int m_can_pci_probe(struct pci_dev *pci, const struct pci_device_id *id) mcan_class->dev = &pci->dev; mcan_class->net->irq = pci_irq_vector(pci, 0); mcan_class->pm_clock_support = 1; - mcan_class->bit_timing = cfg->bit_timing; - mcan_class->data_timing = cfg->data_timing; - mcan_class->can.clock.freq = cfg->clock_freq; + mcan_class->can.clock.freq = id->driver_data; mcan_class->ops = &m_can_pci_ops;

pci_set_drvdata(pci, mcan_class); @@ -218,8 +178,8 @@ static SIMPLE_DEV_PM_OPS(m_can_pci_pm_ops, m_can_pci_suspend, m_can_pci_resume);

static const struct pci_device_id m_can_pci_id_table[] = { - { PCI_VDEVICE(INTEL, 0x4bc1), (kernel_ulong_t)&m_can_pci_ehl, }, - { PCI_VDEVICE(INTEL, 0x4bc2), (kernel_ulong_t)&m_can_pci_ehl, }, + { PCI_VDEVICE(INTEL, 0x4bc1), M_CAN_CLOCK_FREQ_EHL, }, + { PCI_VDEVICE(INTEL, 0x4bc2), M_CAN_CLOCK_FREQ_EHL, }, { } /* Terminating Entry */ }; MODULE_DEVICE_TABLE(pci, m_can_pci_id_table);

base-commit: f3f19f939c11925dadd3f4776f99f8c278a7017b