[PATCH v3] i2c: designware: add reset interface
From: arnd@arndb.de (Arnd Bergmann)
Date: 2017-01-04 14:55:24
Also in:
linux-i2c
On Friday, December 23, 2016 9:40:51 PM CET Zhangfei Gao wrote:
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@@ -176,6 +177,14 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) dev->irq = irq; platform_set_drvdata(pdev, dev); + dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); + if (IS_ERR(dev->rst)) { + if (PTR_ERR(dev->rst) == -EPROBE_DEFER) + return -EPROBE_DEFER; + } else { + reset_control_deassert(dev->rst); + } +
Sorry for the late reply, I only now stumbled over this. I think it's generally wrong to ignore any error aside from -EPROBE_DEFER. It's better to single-out the error conditions you want to ignore (e.g. no reset specified) and ignore those but return an error for all other problems.
quoted hunk ↗ jump to hunk
@@ -270,10 +280,18 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) } r = i2c_dw_probe(dev); - if (r && !dev->pm_runtime_disabled) - pm_runtime_disable(&pdev->dev); + if (r) + goto exit_probe; return r; + +exit_probe: + if (!dev->pm_runtime_disabled) + pm_runtime_disable(&pdev->dev); +exit_reset: + if (!IS_ERR_OR_NULL(dev->rst)) + reset_control_assert(dev->rst); + return r;
try to avoid the IS_ERR_OR_NULL() check, it usually indicates either a bad interface, or that the interface is used wrong. In this case, I think we can't get here with a NULL dev->rst pointer, so it's better to only check IS_ERR, or to explicitly set the pointer to NULL in case there is no reset line. Arnd