On 09/18/2012 07:15 PM, Bo Shen wrote: > Hi Stephen Warren, > > On 9/18/2012 22:51, Stephen Warren wrote: >> On 09/18/2012 03:02 AM, Bo Shen wrote: >>> When i2c-gpio node number is greater than 1, the second can not >>> sucessfully >>> regiter >>> >>> Using alias method to get the pdev->id, or else the second device >>> will use >>> the same id which will cause fail to register >> >> pdev->id shouldn't be used at all with device tree. Why does >> registration fail without this change? > > I add the debug info, and it give the following error without this patch. > > --<8---------------------------------- > adap->name = i2c-gpio-1 > i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL) > adap->name = i2c-gpio-1 > i2c-gpio: probe of i2c.3 failed with error -16 > -->8---------------------------------- > > With this patch, it successfully registered. > --<8---------------------------------- > adap->name = i2c-gpio0 > i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL) > adap->name = i2c-gpio1 > i2c-gpio i2c.3: using pins 90 (SDA) and 91 (SCL) > -->8---------------------------------- Yes, that explains why the registration fails, but not why this patch is the correct solution to the problem. The problematic code appears to be: snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id); Instead, I think that should be something more like: adap->name = dev_name(&pdev->dev); or perhaps: if (pdev->dev.of_node) /* named will be based on DT node name */ adap->name = dev_name(&pdev->dev); else snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id); ? -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
