From 197656de8d1e119f594dd1fe1b2d54fd2ae2add9 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Thu, 22 Oct 2020 23:13:42 +0200 Subject: can: mcp251xfd: mcp251xfd_chip_wait_for_osc_ready(): improve chip detection and error handling The function mcp251xfd_chip_wait_for_osc_ready() polls the Oscillator Control Register for the oscillator to get ready. This is the first register the driver reads from. Reading implausible values (all bits set or unset) can be caused by the chip starting up after power on, waking up after sleep, or by the chip not being preset at all. Add check for implausible register content mcp251xfd_reg_invalid() to the regmap_read_poll_timeout() loop. In case of a regmap_read_poll_timeout() returns a fatal error (and not a timeout), forward it to the caller. As mcp251xfd_chip_wait_for_osc_ready() will be called after the probe function has finished, (currently during ifup), move error message about failed chip detection from there into the probe function. Link: https://lore.kernel.org/all/20220207131047.282110-8-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index 6222633ee7d9..68518e8410dd 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -254,22 +254,25 @@ mcp251xfd_chip_wait_for_osc_ready(const struct mcp251xfd_priv *priv, int err; err = regmap_read_poll_timeout(priv->map_reg, MCP251XFD_REG_OSC, osc, + !mcp251xfd_reg_invalid(osc) && (osc & osc_mask) == osc_reference, MCP251XFD_OSC_STAB_SLEEP_US, MCP251XFD_OSC_STAB_TIMEOUT_US); + if (err != -ETIMEDOUT) + return err; + if (mcp251xfd_reg_invalid(osc)) { netdev_err(priv->ndev, - "Failed to detect %s (osc=0x%08x).\n", - mcp251xfd_get_model_str(priv), osc); + "Failed to read Oscillator Configuration Register (osc=0x%08x).\n", + osc); return -ENODEV; - } else if (err == -ETIMEDOUT) { - netdev_err(priv->ndev, - "Timeout waiting for Oscillator Ready (osc=0x%08x, osc_reference=0x%08x)\n", - osc, osc_reference); - return -ETIMEDOUT; } - return 0; + netdev_err(priv->ndev, + "Timeout waiting for Oscillator Ready (osc=0x%08x, osc_reference=0x%08x)\n", + osc, osc_reference); + + return -ETIMEDOUT; } static int mcp251xfd_chip_clock_enable(const struct mcp251xfd_priv *priv) @@ -1965,8 +1968,11 @@ static int mcp251xfd_probe(struct spi_device *spi) goto out_free_candev; err = mcp251xfd_register(priv); - if (err) + if (err) { + dev_err_probe(&spi->dev, err, "Failed to detect %s.\n", + mcp251xfd_get_model_str(priv)); goto out_can_rx_offload_del; + } return 0; -- cgit v1.2.3