| Message ID | 20240530105801.3930087-1-martin@geanix.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v3] can: m_can: don't enable transceiver when probing | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Series ignored based on subject |
Hi Martin, kernel test robot noticed the following build warnings: [auto build test WARNING on mkl-can-next/testing] [also build test WARNING on linus/master v6.10-rc1 next-20240529] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Martin-Hundeb-ll/can-m_can-don-t-enable-transceiver-when-probing/20240530-185906 base: https://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git testing patch link: https://lore.kernel.org/r/20240530105801.3930087-1-martin%40geanix.com patch subject: [PATCH v3] can: m_can: don't enable transceiver when probing config: i386-buildonly-randconfig-003-20240530 (https://download.01.org/0day-ci/archive/20240530/202405302307.MKjlGruk-lkp@intel.com/config) compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240530/202405302307.MKjlGruk-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202405302307.MKjlGruk-lkp@intel.com/ All warnings (new ones prefixed by >>): >> drivers/net/can/m_can/m_can.c:1725:11: warning: variable 'err' is uninitialized when used here [-Wuninitialized] 1725 | return err; | ^~~ drivers/net/can/m_can/m_can.c:1674:24: note: initialize the variable 'err' to silence this warning 1674 | int m_can_version, err, niso; | ^ | = 0 1 warning generated. vim +/err +1725 drivers/net/can/m_can/m_can.c 1670 1671 static int m_can_dev_setup(struct m_can_classdev *cdev) 1672 { 1673 struct net_device *dev = cdev->net; 1674 int m_can_version, err, niso; 1675 1676 m_can_version = m_can_check_core_release(cdev); 1677 /* return if unsupported version */ 1678 if (!m_can_version) { 1679 dev_err(cdev->dev, "Unsupported version number: %2d", 1680 m_can_version); 1681 return -EINVAL; 1682 } 1683 1684 if (!cdev->is_peripheral) 1685 netif_napi_add(dev, &cdev->napi, m_can_poll); 1686 1687 /* Shared properties of all M_CAN versions */ 1688 cdev->version = m_can_version; 1689 cdev->can.do_set_mode = m_can_set_mode; 1690 cdev->can.do_get_berr_counter = m_can_get_berr_counter; 1691 1692 /* Set M_CAN supported operations */ 1693 cdev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | 1694 CAN_CTRLMODE_LISTENONLY | 1695 CAN_CTRLMODE_BERR_REPORTING | 1696 CAN_CTRLMODE_FD | 1697 CAN_CTRLMODE_ONE_SHOT; 1698 1699 /* Set properties depending on M_CAN version */ 1700 switch (cdev->version) { 1701 case 30: 1702 /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */ 1703 err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); 1704 if (err) 1705 return err; 1706 cdev->can.bittiming_const = &m_can_bittiming_const_30X; 1707 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_30X; 1708 break; 1709 case 31: 1710 /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */ 1711 err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); 1712 if (err) 1713 return err; 1714 cdev->can.bittiming_const = &m_can_bittiming_const_31X; 1715 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X; 1716 break; 1717 case 32: 1718 case 33: 1719 /* Support both MCAN version v3.2.x and v3.3.0 */ 1720 cdev->can.bittiming_const = &m_can_bittiming_const_31X; 1721 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X; 1722 1723 niso = m_can_niso_supported(cdev); 1724 if (niso < 0) > 1725 return err; 1726 if (niso) 1727 cdev->can.ctrlmode_supported |= CAN_CTRLMODE_FD_NON_ISO; 1728 break; 1729 default: 1730 dev_err(cdev->dev, "Unsupported version number: %2d", 1731 cdev->version); 1732 return -EINVAL; 1733 } 1734 1735 /* Forcing standby mode should be redunant, as the chip should be in 1736 * standby after a reset. Write the INIT bit anyways, should the chip 1737 * be configured by previous stage. 1738 */ 1739 return m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT); 1740 } 1741
On Thu, May 30, 2024 at 12:57:58PM +0200, Martin Hundebøll wrote: > The m_can driver sets and clears the CCCR.INIT bit during probe (both > when testing the NON-ISO bit, and when configuring the chip). After > clearing the CCCR.INIT bit, the transceiver enters normal mode, where it > affects the CAN bus (i.e. it ACKs frames). This can cause troubles when > the m_can node is only used for monitoring the bus, as one cannot setup > listen-only mode before the device is probed. > > Rework the probe flow, so that the CCCR.INIT bit is only cleared when > upping the device. First, the tcan4x5x driver is changed to stay in > standby mode during/after probe. This in turn requires changes when > setting bits in the CCCR register, as its CSR and CSA bits are always > high in standby mode. > > Signed-off-by: Martin Hundebøll <martin@geanix.com> > --- > drivers/net/can/m_can/m_can.c | 169 ++++++++++++++++---------- > drivers/net/can/m_can/tcan4x5x-core.c | 13 +- > 2 files changed, 116 insertions(+), 66 deletions(-) > > diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c ... > @@ -1694,21 +1732,26 @@ static int m_can_dev_setup(struct m_can_classdev *cdev) > return -EINVAL; > } > > - if (cdev->ops->init) > - cdev->ops->init(cdev); > - > - return 0; > + /* Forcing standby mode should be redunant, as the chip should be in Hi Martin, A minor nit from my side as it looks like there will be another revision anyway. redunant -> redundant > + * standby after a reset. Write the INIT bit anyways, should the chip > + * be configured by previous stage. > + */ > + return m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT); > } ...
Hi Martin,
kernel test robot noticed the following build warnings:
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Martin-Hundeb-ll/can-m_can-don-t-enable-transceiver-when-probing/20240530-185906
base: https://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git testing
patch link: https://lore.kernel.org/r/20240530105801.3930087-1-martin%40geanix.com
patch subject: [PATCH v3] can: m_can: don't enable transceiver when probing
config: i386-randconfig-r081-20240603 (https://download.01.org/0day-ci/archive/20240603/202406031513.ByfTbHww-lkp@intel.com/config)
compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202406031513.ByfTbHww-lkp@intel.com/
New smatch warnings:
drivers/net/can/m_can/m_can.c:1725 m_can_dev_setup() error: uninitialized symbol 'err'.
vim +/err +1725 drivers/net/can/m_can/m_can.c
3b464affd89821 Marc Kleine-Budde 2020-12-12 1671 static int m_can_dev_setup(struct m_can_classdev *cdev)
e0d1f4816f2a7e Dong Aisheng 2014-07-16 1672 {
3b464affd89821 Marc Kleine-Budde 2020-12-12 1673 struct net_device *dev = cdev->net;
e96c73eab56aed Martin Hundebøll 2024-05-30 1674 int m_can_version, err, niso;
e0d1f4816f2a7e Dong Aisheng 2014-07-16 1675
3b464affd89821 Marc Kleine-Budde 2020-12-12 1676 m_can_version = m_can_check_core_release(cdev);
b03cfc5bb0e11f Mario Huettel 2017-04-08 1677 /* return if unsupported version */
b03cfc5bb0e11f Mario Huettel 2017-04-08 1678 if (!m_can_version) {
3b464affd89821 Marc Kleine-Budde 2020-12-12 1679 dev_err(cdev->dev, "Unsupported version number: %2d",
5e520edd91f0cd Faiz Abbas 2018-01-16 1680 m_can_version);
5e520edd91f0cd Faiz Abbas 2018-01-16 1681 return -EINVAL;
b03cfc5bb0e11f Mario Huettel 2017-04-08 1682 }
b03cfc5bb0e11f Mario Huettel 2017-04-08 1683
3b464affd89821 Marc Kleine-Budde 2020-12-12 1684 if (!cdev->is_peripheral)
b48b89f9c189d2 Jakub Kicinski 2022-09-27 1685 netif_napi_add(dev, &cdev->napi, m_can_poll);
e0d1f4816f2a7e Dong Aisheng 2014-07-16 1686
b03cfc5bb0e11f Mario Huettel 2017-04-08 1687 /* Shared properties of all M_CAN versions */
3b464affd89821 Marc Kleine-Budde 2020-12-12 1688 cdev->version = m_can_version;
3b464affd89821 Marc Kleine-Budde 2020-12-12 1689 cdev->can.do_set_mode = m_can_set_mode;
3b464affd89821 Marc Kleine-Budde 2020-12-12 1690 cdev->can.do_get_berr_counter = m_can_get_berr_counter;
6cfda7fbebe8a4 Oliver Hartkopp 2015-01-05 1691
b03cfc5bb0e11f Mario Huettel 2017-04-08 1692 /* Set M_CAN supported operations */
3b464affd89821 Marc Kleine-Budde 2020-12-12 1693 cdev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
e0d1f4816f2a7e Dong Aisheng 2014-07-16 1694 CAN_CTRLMODE_LISTENONLY |
80646733f11c2e Dong Aisheng 2014-11-18 1695 CAN_CTRLMODE_BERR_REPORTING |
fb7d6a81c22017 Pankaj Sharma 2019-10-21 1696 CAN_CTRLMODE_FD |
fb7d6a81c22017 Pankaj Sharma 2019-10-21 1697 CAN_CTRLMODE_ONE_SHOT;
e0d1f4816f2a7e Dong Aisheng 2014-07-16 1698
b03cfc5bb0e11f Mario Huettel 2017-04-08 1699 /* Set properties depending on M_CAN version */
3b464affd89821 Marc Kleine-Budde 2020-12-12 1700 switch (cdev->version) {
b03cfc5bb0e11f Mario Huettel 2017-04-08 1701 case 30:
b03cfc5bb0e11f Mario Huettel 2017-04-08 1702 /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
7d4a101c0bd3c6 Vincent Mailhol 2021-12-14 1703 err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
7d4a101c0bd3c6 Vincent Mailhol 2021-12-14 1704 if (err)
7d4a101c0bd3c6 Vincent Mailhol 2021-12-14 1705 return err;
d6da7881020f9b Jarkko Nikula 2022-05-12 1706 cdev->can.bittiming_const = &m_can_bittiming_const_30X;
d6da7881020f9b Jarkko Nikula 2022-05-12 1707 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_30X;
b03cfc5bb0e11f Mario Huettel 2017-04-08 1708 break;
b03cfc5bb0e11f Mario Huettel 2017-04-08 1709 case 31:
b03cfc5bb0e11f Mario Huettel 2017-04-08 1710 /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
7d4a101c0bd3c6 Vincent Mailhol 2021-12-14 1711 err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
7d4a101c0bd3c6 Vincent Mailhol 2021-12-14 1712 if (err)
7d4a101c0bd3c6 Vincent Mailhol 2021-12-14 1713 return err;
d6da7881020f9b Jarkko Nikula 2022-05-12 1714 cdev->can.bittiming_const = &m_can_bittiming_const_31X;
d6da7881020f9b Jarkko Nikula 2022-05-12 1715 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
b03cfc5bb0e11f Mario Huettel 2017-04-08 1716 break;
b03cfc5bb0e11f Mario Huettel 2017-04-08 1717 case 32:
5c7d55bded77da Pankaj Sharma 2020-11-26 1718 case 33:
5c7d55bded77da Pankaj Sharma 2020-11-26 1719 /* Support both MCAN version v3.2.x and v3.3.0 */
d6da7881020f9b Jarkko Nikula 2022-05-12 1720 cdev->can.bittiming_const = &m_can_bittiming_const_31X;
d6da7881020f9b Jarkko Nikula 2022-05-12 1721 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
f524f829b75a7d Dan Murphy 2019-05-09 1722
e96c73eab56aed Martin Hundebøll 2024-05-30 1723 niso = m_can_niso_supported(cdev);
e96c73eab56aed Martin Hundebøll 2024-05-30 1724 if (niso < 0)
e96c73eab56aed Martin Hundebøll 2024-05-30 @1725 return err;
s/err/niso/
e96c73eab56aed Martin Hundebøll 2024-05-30 1726 if (niso)
e96c73eab56aed Martin Hundebøll 2024-05-30 1727 cdev->can.ctrlmode_supported |= CAN_CTRLMODE_FD_NON_ISO;
b03cfc5bb0e11f Mario Huettel 2017-04-08 1728 break;
b03cfc5bb0e11f Mario Huettel 2017-04-08 1729 default:
3b464affd89821 Marc Kleine-Budde 2020-12-12 1730 dev_err(cdev->dev, "Unsupported version number: %2d",
3b464affd89821 Marc Kleine-Budde 2020-12-12 1731 cdev->version);
5e520edd91f0cd Faiz Abbas 2018-01-16 1732 return -EINVAL;
b03cfc5bb0e11f Mario Huettel 2017-04-08 1733 }
b03cfc5bb0e11f Mario Huettel 2017-04-08 1734
e96c73eab56aed Martin Hundebøll 2024-05-30 1735 /* Forcing standby mode should be redunant, as the chip should be in
e96c73eab56aed Martin Hundebøll 2024-05-30 1736 * standby after a reset. Write the INIT bit anyways, should the chip
e96c73eab56aed Martin Hundebøll 2024-05-30 1737 * be configured by previous stage.
e96c73eab56aed Martin Hundebøll 2024-05-30 1738 */
e96c73eab56aed Martin Hundebøll 2024-05-30 1739 return m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT);
e0d1f4816f2a7e Dong Aisheng 2014-07-16 1740 }
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 14b231c4d7ec..0f74ab249b35 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -379,38 +379,72 @@ m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset, u32 *val) return cdev->ops->read_fifo(cdev, addr_offset, val, 1); } -static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable) +static int m_can_cccr_update_bits(struct m_can_classdev *cdev, u32 mask, u32 val) { - u32 cccr = m_can_read(cdev, M_CAN_CCCR); - u32 timeout = 10; - u32 val = 0; - - /* Clear the Clock stop request if it was set */ - if (cccr & CCCR_CSR) - cccr &= ~CCCR_CSR; - - if (enable) { - /* enable m_can configuration */ - m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT); - udelay(5); - /* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */ - m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE); - } else { - m_can_write(cdev, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE)); + u32 val_before = m_can_read(cdev, M_CAN_CCCR); + u32 val_after = (val_before & ~mask) | val; + size_t tries = 10; + + if (!(mask & CCCR_INIT) && !(val_before & CCCR_INIT)) { + dev_err(cdev->dev, + "refusing to configure device when in normal mode\n"); + return -EBUSY; } - /* there's a delay for module initialization */ - if (enable) - val = CCCR_INIT | CCCR_CCE; - - while ((m_can_read(cdev, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) { - if (timeout == 0) { - netdev_warn(cdev->net, "Failed to init module\n"); - return; - } - timeout--; - udelay(1); + /* The chip should be in standby mode when changing the CCCR register, + * and some chips set the CSR and CSA bits when in standby. Furthermore, + * the CSR and CSA bits should be written as zeros, even when they read + * ones. + */ + val_after &= ~(CCCR_CSR | CCCR_CSA); + + while (tries--) { + u32 val_read; + + /* Write the desired value in each try, as setting some bits in + * the CCCR register require other bits to be set first. E.g. + * setting the NISO bit requires setting the CCE bit first. + */ + m_can_write(cdev, M_CAN_CCCR, val_after); + + val_read = m_can_read(cdev, M_CAN_CCCR) & ~(CCCR_CSR | CCCR_CSA); + + if (val_read == val_after) + return 0; + + usleep_range(1, 5); } + + return -ETIMEDOUT; +} + +static int m_can_config_enable(struct m_can_classdev *cdev) +{ + int err; + + /* CCCR_INIT must be set in order to set CCCR_CCE, but access to + * configuration registers should only be enabled when in standby mode, + * where CCCR_INIT is always set. + */ + err = m_can_cccr_update_bits(cdev, CCCR_CCE, CCCR_CCE); + if (err) + netdev_err(cdev->net, "failed to enable configuration mode\n"); + + return err; +} + +static int m_can_config_disable(struct m_can_classdev *cdev) +{ + int err; + + /* Only clear CCCR_CCE, since CCCR_INIT cannot be cleared while in + * standby mode + */ + err = m_can_cccr_update_bits(cdev, CCCR_CCE, 0); + if (err) + netdev_err(cdev->net, "failed to disable configuration registers\n"); + + return err; } static void m_can_interrupt_enable(struct m_can_classdev *cdev, u32 interrupts) @@ -1403,7 +1437,9 @@ static int m_can_chip_config(struct net_device *dev) interrupts &= ~(IR_ARA | IR_ELO | IR_DRX | IR_TEFF | IR_TFE | IR_TCF | IR_HPM | IR_RF1F | IR_RF1W | IR_RF1N | IR_RF0F); - m_can_config_endisable(cdev, true); + err = m_can_config_enable(cdev); + if (err) + return err; /* RX Buffer/FIFO Element Size 64 bytes data field */ m_can_write(cdev, M_CAN_RXESC, @@ -1521,7 +1557,9 @@ static int m_can_chip_config(struct net_device *dev) FIELD_PREP(TSCC_TCP_MASK, 0xf) | FIELD_PREP(TSCC_TSS_MASK, TSCC_TSS_INTERNAL)); - m_can_config_endisable(cdev, false); + err = m_can_config_disable(cdev); + if (err) + return err; if (cdev->ops->init) cdev->ops->init(cdev); @@ -1550,7 +1588,11 @@ static int m_can_start(struct net_device *dev) cdev->tx_fifo_putidx = FIELD_GET(TXFQS_TFQPI_MASK, m_can_read(cdev, M_CAN_TXFQS)); - return 0; + ret = m_can_cccr_update_bits(cdev, CCCR_INIT, 0); + if (ret) + netdev_err(dev, "failed to enter normal mode\n"); + + return ret; } static int m_can_set_mode(struct net_device *dev, enum can_mode mode) @@ -1599,43 +1641,37 @@ static int m_can_check_core_release(struct m_can_classdev *cdev) } /* Selectable Non ISO support only in version 3.2.x - * This function checks if the bit is writable. + * Return 1 if the bit is writable, 0 if it is not, or negative on error. */ -static bool m_can_niso_supported(struct m_can_classdev *cdev) +static int m_can_niso_supported(struct m_can_classdev *cdev) { - u32 cccr_reg, cccr_poll = 0; - int niso_timeout = -ETIMEDOUT; - int i; + int ret, niso; - m_can_config_endisable(cdev, true); - cccr_reg = m_can_read(cdev, M_CAN_CCCR); - cccr_reg |= CCCR_NISO; - m_can_write(cdev, M_CAN_CCCR, cccr_reg); + ret = m_can_config_enable(cdev); + if (ret) + return ret; - for (i = 0; i <= 10; i++) { - cccr_poll = m_can_read(cdev, M_CAN_CCCR); - if (cccr_poll == cccr_reg) { - niso_timeout = 0; - break; - } + /* First try to set the NISO bit. */ + niso = m_can_cccr_update_bits(cdev, CCCR_NISO, CCCR_NISO); - usleep_range(1, 5); + /* Then clear the it again. */ + ret = m_can_cccr_update_bits(cdev, CCCR_NISO, 0); + if (ret) { + dev_err(cdev->dev, "failed to revert the NON-ISO bit in CCCR\n"); + return ret; } - /* Clear NISO */ - cccr_reg &= ~(CCCR_NISO); - m_can_write(cdev, M_CAN_CCCR, cccr_reg); + ret = m_can_config_disable(cdev); + if (ret) + return ret; - m_can_config_endisable(cdev, false); - - /* return false if time out (-ETIMEDOUT), else return true */ - return !niso_timeout; + return niso == 0; } static int m_can_dev_setup(struct m_can_classdev *cdev) { struct net_device *dev = cdev->net; - int m_can_version, err; + int m_can_version, err, niso; m_can_version = m_can_check_core_release(cdev); /* return if unsupported version */ @@ -1684,9 +1720,11 @@ static int m_can_dev_setup(struct m_can_classdev *cdev) cdev->can.bittiming_const = &m_can_bittiming_const_31X; cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X; - cdev->can.ctrlmode_supported |= - (m_can_niso_supported(cdev) ? - CAN_CTRLMODE_FD_NON_ISO : 0); + niso = m_can_niso_supported(cdev); + if (niso < 0) + return err; + if (niso) + cdev->can.ctrlmode_supported |= CAN_CTRLMODE_FD_NON_ISO; break; default: dev_err(cdev->dev, "Unsupported version number: %2d", @@ -1694,21 +1732,26 @@ static int m_can_dev_setup(struct m_can_classdev *cdev) return -EINVAL; } - if (cdev->ops->init) - cdev->ops->init(cdev); - - return 0; + /* Forcing standby mode should be redunant, as the chip should be in + * standby after a reset. Write the INIT bit anyways, should the chip + * be configured by previous stage. + */ + return m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT); } static void m_can_stop(struct net_device *dev) { struct m_can_classdev *cdev = netdev_priv(dev); + int ret; /* disable all interrupts */ m_can_disable_all_interrupts(cdev); /* Set init mode to disengage from the network */ - m_can_config_endisable(cdev, true); + ret = m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT); + if (ret) + netdev_err(dev, "failed to enter standby mode: %pe\n", + ERR_PTR(ret)); /* set the state as STOPPED */ cdev->can.state = CAN_STATE_STOPPED; diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c index a42600dac70d..d723206ac7c9 100644 --- a/drivers/net/can/m_can/tcan4x5x-core.c +++ b/drivers/net/can/m_can/tcan4x5x-core.c @@ -453,10 +453,17 @@ static int tcan4x5x_can_probe(struct spi_device *spi) goto out_power; } - ret = tcan4x5x_init(mcan_class); + tcan4x5x_check_wake(priv); + + ret = tcan4x5x_write_tcan_reg(mcan_class, TCAN4X5X_INT_EN, 0); if (ret) { - dev_err(&spi->dev, "tcan initialization failed %pe\n", - ERR_PTR(ret)); + dev_err(&spi->dev, "Disabling interrupts failed %pe\n", ERR_PTR(ret)); + goto out_power; + } + + ret = tcan4x5x_clear_interrupts(mcan_class); + if (ret) { + dev_err(&spi->dev, "Clearing interrupts failed %pe\n", ERR_PTR(ret)); goto out_power; }
The m_can driver sets and clears the CCCR.INIT bit during probe (both when testing the NON-ISO bit, and when configuring the chip). After clearing the CCCR.INIT bit, the transceiver enters normal mode, where it affects the CAN bus (i.e. it ACKs frames). This can cause troubles when the m_can node is only used for monitoring the bus, as one cannot setup listen-only mode before the device is probed. Rework the probe flow, so that the CCCR.INIT bit is only cleared when upping the device. First, the tcan4x5x driver is changed to stay in standby mode during/after probe. This in turn requires changes when setting bits in the CCCR register, as its CSR and CSA bits are always high in standby mode. Signed-off-by: Martin Hundebøll <martin@geanix.com> --- drivers/net/can/m_can/m_can.c | 169 ++++++++++++++++---------- drivers/net/can/m_can/tcan4x5x-core.c | 13 +- 2 files changed, 116 insertions(+), 66 deletions(-)