diff mbox series

[net,1/2] Revert "can: m_can: pci: use custom bit timings for Elkhart Lake"

Message ID 20220514185742.407230-2-mkl@pengutronix.de (mailing list archive)
State Accepted
Commit 14ea4a470494528c7e88da5c4116c24eb027059f
Delegated to: Netdev Maintainers
Headers show
Series [net,1/2] Revert "can: m_can: pci: use custom bit timings for Elkhart Lake" | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Pull request is its own cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 1 blamed authors not CCed: matthias.schiffer@ew.tq-group.com; 4 maintainers not CCed: matthias.schiffer@ew.tq-group.com edumazet@google.com wg@grandegger.com pabeni@redhat.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: Unknown commit id '0e8ffdf3b86d', maybe rebased or not pulled? WARNING: Unknown commit id '0e8ffdf3b86dfd44b651f91b12fcae76c25c453b', maybe rebased or not pulled?
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Marc Kleine-Budde May 14, 2022, 6:57 p.m. UTC 
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: ea4c1787685d ("can: m_can: pci: use custom bit timings for Elkhart Lake")
Link: https://lore.kernel.org/all/20220512124144.536850-1-jarkko.nikula@linux.intel.com
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(-)


base-commit: f3f19f939c11925dadd3f4776f99f8c278a7017b

Comments

patchwork-bot+netdevbpf@kernel.org May 16, 2022, 9:10 a.m. UTC | #1 
Hello:

This series was applied to netdev/net.git (master)
by Marc Kleine-Budde <mkl@pengutronix.de>:

On Sat, 14 May 2022 20:57:41 +0200 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [net,1/2] Revert "can: m_can: pci: use custom bit timings for Elkhart Lake"
    https://git.kernel.org/netdev/net/c/14ea4a470494
  - [net,2/2] can: m_can: remove support for custom bit timing, take #2
    https://git.kernel.org/netdev/net/c/d6da7881020f

You are awesome, thank you!
diff mbox series

Patch

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);