Messages in this thread | | | Date | Mon, 3 Nov 2014 19:09:21 +0100 | From | Richard Cochran <> | Subject | Re: [PATCH 0/4] Touchscreen performance related fixes |
| |
On Mon, Oct 27, 2014 at 04:38:27PM +0530, Vignesh R wrote: > This series of patches fix TSC defects related to lag in touchscreen > performance and cursor jump at touch release. The lag was result of > udelay in TSC interrupt handler. Cursor jump due to false pen-up event. > The patches implement Advisory 1.0.31 in silicon errata of am335x-evm > to avoid false pen-up events and remove udelay.
That advisory has two workarounds. You have chosen the second one?
The text of the second workaround says it only works on 4 wire setups, so I wonder how 5 wire designs will be affected.
> The advisory says to use > steps 1 to 4 for ADC and 5 to 16 for TSC (assuming 4 wire TSC and 4 channel > ADC).
No, it doesn't say that. (sprz360f.pdf)
> Further the X co-ordinate must be the last one to be sampled just > before charge step. The first two patches implement the required changes.
FWIW, I implemented the first workaround and removed the udelay not too long ago. Like Sebastian, I saw the TSC unit hang after about 50000 interrupts when running with the workaround.
Did you test you patch for very long?
Thanks, Richard
| |