Messages in this thread | | | Date | Fri, 22 Sep 2017 13:17:02 +0900 | From | Andi Shyti <> | Subject | Re: [PATCH] Input: add support for the Samsung S6SY761 touchscreen |
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Hi Dmitry,
thanks for your review!
[...]
> > +static void s6sy761_report_coordinates(struct s6sy761_data *sdata, u8 *event) > > +{ > > + u8 tid = ((event[0] & S6SY761_MASK_TID) >> 2) - 1; > > Should we make sure that event[0] & S6SY761_MASK_TID is not 0?
I check event[0] already in s6sy761_handle_events (called by the irq handler), if we get here event[0] is for sure positive...
[...]
> > +static void s6sy761_handle_events(struct s6sy761_data *sdata, u8 left_event) > > +{ > > + int i; > > + > > + for (i = 0; i < left_event; i++) { > > + u8 *event = &sdata->data[i * S6SY761_EVENT_SIZE]; > > + u8 event_id = event[0] & S6SY761_MASK_EID; > > + > > + if (!event[0]) > > + return; ^^^^^^^^ ... exactly here.
'!event[0]' means also to me that there is nothing left, therefore I can discard whatever is next (given that there is something left).
> > + switch (event_id) { > > + > > + case S6SY761_EVENT_ID_COORDINATE: > > + s6sy761_handle_coordinates(sdata, event); > > + break; > > + > > + case S6SY761_EVENT_ID_STATUS: > > + break; > > + > > + default: > > + break; > > + } > > + } > > +}
[...]
> > +static ssize_t s6sy761_sysfs_low_power_store(struct device *dev, > > + struct device_attribute *attr, > > + const char *buf, size_t len) > > +{ > > + struct s6sy761_data *sdata = dev_get_drvdata(dev); > > + unsigned long value; > > + s32 ret; > > + u8 new_status; > > + > > + if (kstrtoul(buf, 0, &value)) > > + return -EINVAL; > > + > > + /* > > + * The device does not respond to read/write in low power, > > + * it will enable only in case of external events (e.g. touch). > > + * The i2c read will fail as expected if no external events occur > > + */ > > I am not quite sure how to parse this. Are you saying that the device in > low power mode will wake up when touched? Then your runtime PM > implementation seems incomplete.
I was startled as well when I saw this working. It cannot be in the PM runtime because the device would freeze (unless is touched). I don't know if it's a bug in the firmware or this is how it meant to be.
> In any case, I'd rather we did not expose this state as a custom > attribute.
I can remove it completely, indeed I don't see much use of it.
[...]
> > + sdata->devid = buffer[1] << 8 | buffer[2]; > > get_unaligned_be16()?
Thanks!
[...]
> > + /* check if both max_x and max_y have a value */ > > + if (unlikely(!sdata->prop.max_x || !sdata->prop.max_y)) > > This is not in hot path, we do not need unlikely() here.
OK, Thanks!
> > + return -EINVAL; > > + > > + /* if no tx channels defined, at least keep one */ > > + sdata->tx_channel = !buffer[8] ? 1 : buffer[8]; > > sdata->tx_channel = max(buffer[8], 1);
Thanks!
[...]
> > +static int s6sy761_probe(struct i2c_client *client, > > + const struct i2c_device_id *id) > > +{
[...]
> > + err = devm_request_threaded_irq(&client->dev, client->irq, NULL, > > + s6sy761_irq_handler, > > + IRQF_TRIGGER_LOW | IRQF_ONESHOT, > > + "s6sy761_irq", sdata); > > + if (err) > > + return err; > > + > > + disable_irq(client->irq); > > Can you request IRQ after allocating and setting up the input device? > Then you do not need to check for its presence in the interrupt handler.
The reason I do it here is because the x and y are embedded in the device itself. This means that I first need to enable the device, read x and y and then register the input device.
At power up I might expect an interrupt coming, thus I need to check if 'input' is not 'NULL'.
[...]
> > + err = sysfs_create_group(&sdata->client->dev.kobj, > > + &s6sy761_attribute_group); > > We have devm_device_add_groups() now.
Thanks! I will patch also the other driver I sent, then (the stmfts).
[...]
> Thanks.
Thank you!
Andi
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