2015-05-19 18:14 GMT+09:00 Laurentiu Palcu <laurentiu.palcu@xxxxxxxxx>: > Hi Krzysztof, > > On Tue, May 19, 2015 at 05:40:25PM +0900, Krzysztof Kozlowski wrote: >> > + >> > +static int bq25890_chip_reset(struct bq25890_device *bq) >> > +{ >> > + int ret; >> > + >> > + ret = bq25890_field_write(bq, F_REG_RST, 1); >> > + if (ret < 0) >> > + return ret; >> > + >> > + do { >> > + ret = bq25890_field_read(bq, F_REG_RST); >> > + if (ret < 0) >> > + return ret; >> > + >> > + usleep_range(5, 10); >> > + } while (ret == 1); >> >> Is it possible to loop here indefinetely? > According to specifications, this field is "Reset to 0 after register > reset is completed", so I'm trusting the chip will behave as advertised! > :) We could implement a safety mechanism to avoid looping in case the > chip misbehaves but I don't think it's worth it. What do you think? I just prefer to use some retry counter because it would be better to fail the reset instead of being stuck here. The chip may behave correctly but still a bug could exist in the driver. The retry counter won't be much complicated here also. But I do not insist so if you really think it is not worth it then I am fine. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html