From 8bfd4ec726945cec35ee5cafebc1c55b83d5a9fb Mon Sep 17 00:00:00 2001 From: Carsten Haitzler Date: Mon, 28 Nov 2022 10:51:58 +0000 Subject: i2c: cadence: Fix regression with bus recovery Commit "i2c: cadence: Add standard bus recovery support" breaks for i2c devices that have no pinctrl defined. There is no requirement for this to exist in the DT. This has worked perfectly well without this before in at least 1 real usage case on hardware (Mali Komeda DPU, Cadence i2c to talk to a tda99xx phy). Adding the requirement to have pinctrl set up in the device tree (or otherwise be found) is a regression where the whole i2c device is lost entirely (in this case dropping entire devices which then leads to the drm display stack unable to find the phy for display output, thus having no drm display device and so on down the chain). This converts the above commit to an enhancement if pinctrl can be found for the i2c device, providing a timeout on read with recovery, but if not, do what used to be done rather than a fatal loss of a device. This restores the mentioned display devices to their working state again. Fixes: 58b924241d0a ("i2c: cadence: Add standard bus recovery support") Signed-off-by: Carsten Haitzler Reviewed-by: Shubhrajyoti Datta Reviewed-by: Michael Grzeschik Acked-by: Michal Simek [wsa: added braces to else-branch] Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-cadence.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c index fe0cd205502d..f58943cb1341 100644 --- a/drivers/i2c/busses/i2c-cadence.c +++ b/drivers/i2c/busses/i2c-cadence.c @@ -852,7 +852,8 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, CDNS_I2C_POLL_US, CDNS_I2C_TIMEOUT_US); if (ret) { ret = -EAGAIN; - i2c_recover_bus(adap); + if (id->adap.bus_recovery_info) + i2c_recover_bus(adap); goto out; } @@ -1263,8 +1264,13 @@ static int cdns_i2c_probe(struct platform_device *pdev) id->rinfo.pinctrl = devm_pinctrl_get(&pdev->dev); if (IS_ERR(id->rinfo.pinctrl)) { + int err = PTR_ERR(id->rinfo.pinctrl); + dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n"); - return PTR_ERR(id->rinfo.pinctrl); + if (err != -ENODEV) + return err; + } else { + id->adap.bus_recovery_info = &id->rinfo; } id->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &r_mem); @@ -1283,7 +1289,6 @@ static int cdns_i2c_probe(struct platform_device *pdev) id->adap.retries = 3; /* Default retry value. */ id->adap.algo_data = id; id->adap.dev.parent = &pdev->dev; - id->adap.bus_recovery_info = &id->rinfo; init_completion(&id->xfer_done); snprintf(id->adap.name, sizeof(id->adap.name), "Cadence I2C at %08lx", (unsigned long)r_mem->start); -- cgit v1.2.3