Messages in this thread | | | Date | Wed, 19 Mar 2014 13:27:25 +0200 | From | Roger Quadros <> | Subject | Re: [PATCH v2 4/8] Input: pixcir_i2c_ts: Use Type-B Multi-Touch protocol |
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Henrik,
On 03/10/2014 06:37 PM, Felipe Balbi wrote: > On Mon, Mar 10, 2014 at 10:57:10AM +0200, Roger Quadros wrote: >> Hi Henrik, >> >> On 03/08/2014 05:11 PM, Henrik Rydberg wrote: >>> Hi Roger, >>> >>> the MT implementation seems mostly fine, just one curiosity: >>> >>>> static irqreturn_t pixcir_ts_isr(int irq, void *dev_id) >>>> { >>>> struct pixcir_i2c_ts_data *tsdata = dev_id; >>>> const struct pixcir_ts_platform_data *pdata = tsdata->chip; >>>> + struct pixcir_report_data report; >>>> >>>> while (!tsdata->exiting) { >>>> - pixcir_ts_poscheck(tsdata); >>>> - >>>> - if (gpio_get_value(pdata->gpio_attb)) >>>> + /* parse packet */ >>>> + pixcir_ts_parse(tsdata, &report); >>>> + >>>> + /* report it */ >>>> + pixcir_ts_report(tsdata, &report); >>>> + >>>> + if (gpio_get_value(pdata->gpio_attb)) { >>>> + if (report.num_touches) { >>>> + /* >>>> + * Last report with no finger up? >>>> + * Do it now then. >>>> + */ >>>> + input_mt_sync_frame(tsdata->input); >>>> + input_sync(tsdata->input); >>> >>> Why is this special handling needed? >> >> This is needed because the controller doesn't always report when all fingers >> have left the screen. e.g. report might contain 3 fingers touched and then >> gpio_attb line is de-asserted. There's no report with 0 fingers touched even >> if the user's fingers have left the screen. So we never detect a BUTTON_UP. >> >> Without this s/w workaround we observe side effects like buttons being pressed >> but not released. To me it looks like a bug in the controller. > > the other way would be to *also* use IRQF_TRIGGER_RISING, then you get > an IRQ when fingers leave the screen. No ? >
If you are OK with my explanation and the patches, could you please Ack them? Thanks.
cheers, -roger
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