On Fri, Sep 30, 2016 at 08:22:47PM -0700, Guenter Roeck wrote:
> Sensor tuning support is needed to determine the number of enabled
> tx and rx electrodes for use in F54 functions.
>
> The number of enabled electrodes is not identical to the total number
> of electrodes as reported with F55:Query0 and F55:Query1. It has to be
> calculated by analyzing F55:Ctrl1 (sensor receiver assignment) and
> F55:Ctrl2 (sensor transmitter assignment).
>
> Support for additional sensor tuning functions may be added later.
>
> Signed-off-by: Guenter Roeck <[email protected]>
Ping ... any comments on this patch and on
https://patchwork.kernel.org/patch/9359061/ ?
Both patches now apply to mainline.
Thanks,
Guenter
> ---
> This patch applies to next-20160930.
>
> drivers/input/rmi4/Kconfig | 9 +++
> drivers/input/rmi4/Makefile | 1 +
> drivers/input/rmi4/rmi_bus.c | 3 +
> drivers/input/rmi4/rmi_driver.h | 1 +
> drivers/input/rmi4/rmi_f55.c | 127 ++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 141 insertions(+)
> create mode 100644 drivers/input/rmi4/rmi_f55.c
>
> diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
> index 4c8a55857e00..11ede43c9936 100644
> --- a/drivers/input/rmi4/Kconfig
> +++ b/drivers/input/rmi4/Kconfig
> @@ -72,3 +72,12 @@ config RMI4_F54
>
> Function 54 provides access to various diagnostic features in certain
> RMI4 touch sensors.
> +
> +config RMI4_F55
> + bool "RMI4 Function 55 (Sensor tuning)"
> + depends on RMI4_CORE
> + help
> + Say Y here if you want to add support for RMI4 function 55
> +
> + Function 55 provides access to the RMI4 touch sensor tuning
> + mechanism.
> diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile
> index 0bafc8502c4b..96f8e0c21e3b 100644
> --- a/drivers/input/rmi4/Makefile
> +++ b/drivers/input/rmi4/Makefile
> @@ -8,6 +8,7 @@ rmi_core-$(CONFIG_RMI4_F11) += rmi_f11.o
> rmi_core-$(CONFIG_RMI4_F12) += rmi_f12.o
> rmi_core-$(CONFIG_RMI4_F30) += rmi_f30.o
> rmi_core-$(CONFIG_RMI4_F54) += rmi_f54.o
> +rmi_core-$(CONFIG_RMI4_F55) += rmi_f55.o
>
> # Transports
> obj-$(CONFIG_RMI4_I2C) += rmi_i2c.o
> diff --git a/drivers/input/rmi4/rmi_bus.c b/drivers/input/rmi4/rmi_bus.c
> index ef8c747c35e7..82b7d4960858 100644
> --- a/drivers/input/rmi4/rmi_bus.c
> +++ b/drivers/input/rmi4/rmi_bus.c
> @@ -314,6 +314,9 @@ static struct rmi_function_handler *fn_handlers[] = {
> #ifdef CONFIG_RMI4_F54
> &rmi_f54_handler,
> #endif
> +#ifdef CONFIG_RMI4_F55
> + &rmi_f55_handler,
> +#endif
> };
>
> static void __rmi_unregister_function_handlers(int start_idx)
> diff --git a/drivers/input/rmi4/rmi_driver.h b/drivers/input/rmi4/rmi_driver.h
> index 8dfbebe9bf86..a65cf70f61e2 100644
> --- a/drivers/input/rmi4/rmi_driver.h
> +++ b/drivers/input/rmi4/rmi_driver.h
> @@ -103,4 +103,5 @@ extern struct rmi_function_handler rmi_f11_handler;
> extern struct rmi_function_handler rmi_f12_handler;
> extern struct rmi_function_handler rmi_f30_handler;
> extern struct rmi_function_handler rmi_f54_handler;
> +extern struct rmi_function_handler rmi_f55_handler;
> #endif
> diff --git a/drivers/input/rmi4/rmi_f55.c b/drivers/input/rmi4/rmi_f55.c
> new file mode 100644
> index 000000000000..268fa904205a
> --- /dev/null
> +++ b/drivers/input/rmi4/rmi_f55.c
> @@ -0,0 +1,127 @@
> +/*
> + * Copyright (c) 2012-2015 Synaptics Incorporated
> + * Copyright (C) 2016 Zodiac Inflight Innovations
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/input.h>
> +#include <linux/kernel.h>
> +#include <linux/rmi.h>
> +#include <linux/slab.h>
> +#include "rmi_driver.h"
> +
> +#define F55_NAME "rmi4_f55"
> +
> +/* F55 data offsets */
> +#define F55_NUM_RX_OFFSET 0
> +#define F55_NUM_TX_OFFSET 1
> +#define F55_PHYS_CHAR_OFFSET 2
> +
> +/* Fixed sizes of reports */
> +#define F55_QUERY_LEN 17
> +
> +/* F55 capabilities */
> +#define F55_CAP_SENSOR_ASSIGN BIT(0)
> +
> +struct f55_data {
> + struct rmi_function *fn;
> +
> + u8 qry[F55_QUERY_LEN];
> + u8 num_rx_electrodes;
> + u8 cfg_num_rx_electrodes;
> + u8 num_tx_electrodes;
> + u8 cfg_num_tx_electrodes;
> +};
> +
> +static int rmi_f55_detect(struct rmi_function *fn)
> +{
> + struct f55_data *f55;
> + int error;
> +
> + f55 = dev_get_drvdata(&fn->dev);
> +
> + error = rmi_read_block(fn->rmi_dev, fn->fd.query_base_addr,
> + &f55->qry, sizeof(f55->qry));
> + if (error) {
> + dev_err(&fn->dev, "%s: Failed to query F55 properties\n",
> + __func__);
> + return error;
> + }
> +
> + f55->num_rx_electrodes = f55->qry[F55_NUM_RX_OFFSET];
> + f55->num_tx_electrodes = f55->qry[F55_NUM_TX_OFFSET];
> +
> + f55->cfg_num_rx_electrodes = f55->num_rx_electrodes;
> + f55->cfg_num_tx_electrodes = f55->num_rx_electrodes;
> +
> + if (f55->qry[F55_PHYS_CHAR_OFFSET] & F55_CAP_SENSOR_ASSIGN) {
> + int i, total;
> + u8 buf[256];
> +
> + /*
> + * Calculate the number of enabled receive and transmit
> + * electrodes by reading F55:Ctrl1 (sensor receiver assignment)
> + * and F55:Ctrl2 (sensor transmitter assignment). The number of
> + * enabled electrodes is the sum of all field entries with a
> + * value other than 0xff.
> + */
> + error = rmi_read_block(fn->rmi_dev,
> + fn->fd.control_base_addr + 1,
> + buf, f55->num_rx_electrodes);
> + if (!error) {
> + total = 0;
> + for (i = 0; i < f55->num_rx_electrodes; i++) {
> + if (buf[i] != 0xff)
> + total++;
> + }
> + f55->cfg_num_rx_electrodes = total;
> + }
> +
> + error = rmi_read_block(fn->rmi_dev,
> + fn->fd.control_base_addr + 2,
> + buf, f55->num_tx_electrodes);
> + if (!error) {
> + total = 0;
> + for (i = 0; i < f55->num_tx_electrodes; i++) {
> + if (buf[i] != 0xff)
> + total++;
> + }
> + f55->cfg_num_tx_electrodes = total;
> + }
> + }
> +
> + rmi_dbg(RMI_DEBUG_FN, &fn->dev, "F55 num_rx_electrodes: %d (raw %d)\n",
> + f55->cfg_num_rx_electrodes, f55->num_rx_electrodes);
> + rmi_dbg(RMI_DEBUG_FN, &fn->dev, "F55 num_tx_electrodes: %d (raw %d)\n",
> + f55->cfg_num_tx_electrodes, f55->num_tx_electrodes);
> +
> + return 0;
> +}
> +
> +static int rmi_f55_probe(struct rmi_function *fn)
> +{
> + struct f55_data *f55;
> +
> + f55 = devm_kzalloc(&fn->dev, sizeof(struct f55_data), GFP_KERNEL);
> + if (!f55)
> + return -ENOMEM;
> +
> + f55->fn = fn;
> + dev_set_drvdata(&fn->dev, f55);
> +
> + return rmi_f55_detect(fn);
> +}
> +
> +struct rmi_function_handler rmi_f55_handler = {
> + .driver = {
> + .name = F55_NAME,
> + },
> + .func = 0x55,
> + .probe = rmi_f55_probe,
> +};
On Mon, Oct 17, 2016 at 02:30:08PM -0700, Guenter Roeck wrote:
> On Fri, Sep 30, 2016 at 08:22:47PM -0700, Guenter Roeck wrote:
> > Sensor tuning support is needed to determine the number of enabled
> > tx and rx electrodes for use in F54 functions.
> >
> > The number of enabled electrodes is not identical to the total number
> > of electrodes as reported with F55:Query0 and F55:Query1. It has to be
> > calculated by analyzing F55:Ctrl1 (sensor receiver assignment) and
> > F55:Ctrl2 (sensor transmitter assignment).
> >
> > Support for additional sensor tuning functions may be added later.
> >
> > Signed-off-by: Guenter Roeck <[email protected]>
>
> Ping ... any comments on this patch and on
> https://patchwork.kernel.org/patch/9359061/ ?
>
> Both patches now apply to mainline.
>
> Thanks,
> Guenter
Hi Guenter-
I've reviewed and tested (on S7300 and S7813) both these patches now
- you can add my sign-off.
However, on the S7813 firmware, F55 is on PDT page 3, and nothing
on page 2, so the default behaviour of the mainline driver means it is
not initialised.
So I think we need to revert this change in mainline:
https://patchwork.kernel.org/patch/3796971/
See below the PDT scan with it reverted and some debug added.
Christopher/Andrew: is there a better heuristic than scanning all 255
pages, given that some firmwares contain gaps?
cheers
Nick
[ 2.181199] rmi4_physical rmi4-00: Creating functions.
[ 2.181210] rmi4_physical rmi4-00: rmi_scan_pdt page 0
[ 2.181221] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 233
[ 2.182218] rmi4_physical rmi4-00: rmi_read_pdt_entry: F34 V2
[ 2.182230] rmi4_physical rmi4-00: Initializing F34.
[ 2.182325] rmi4_physical rmi4-00: Registered F34.
[ 2.182337] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 227
[ 2.183003] rmi4_physical rmi4-00: rmi_read_pdt_entry: F01 V0
[ 2.183014] rmi4_physical rmi4-00: Initializing F01.
[ 2.187358] rmi4_f01 rmi4-00.fn01: found RMI device, manufacturer: Synaptics, product: s7813, fw id: 2174259
[ 2.198822] rmi4_physical rmi4-00: Registered F01.
[ 2.198834] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 221
[ 2.199494] rmi4_physical rmi4-00: rmi_read_pdt_entry: F12 V0
[ 2.199505] rmi4_physical rmi4-00: Initializing F12.
[ 2.199612] rmi4_f12 rmi4-00.fn12: rmi_f12_probe
[ 2.210721] rmi4_physical rmi4-00: Registered F12.
[ 2.210732] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 215
[ 2.211393] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
[ 2.211404] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
[ 2.211414] rmi4_physical rmi4-00: rmi_scan_pdt page 1
[ 2.211424] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 489
[ 2.212419] rmi4_physical rmi4-00: rmi_read_pdt_entry: F54 V0
[ 2.212431] rmi4_physical rmi4-00: Initializing F54.
[ 2.214241] rmi4_f54 rmi4-00.fn54: F54 num_rx_electrodes: 60
[ 2.214253] rmi4_f54 rmi4-00.fn54: F54 num_tx_electrodes: 36
[ 2.214263] rmi4_f54 rmi4-00.fn54: F54 capabilities: 0x44
[ 2.214274] rmi4_f54 rmi4-00.fn54: F54 clock rate: 0x5aa0
[ 2.214283] rmi4_f54 rmi4-00.fn54: F54 family: 0x2
[ 2.214695] rmi4_physical rmi4-00: Registered F54.
[ 2.214708] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 483
[ 2.215372] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
[ 2.215384] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
[ 2.215395] rmi4_physical rmi4-00: rmi_scan_pdt page 2
[ 2.215405] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 745
[ 2.216404] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
[ 2.216415] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
[ 2.216426] rmi4_physical rmi4-00: rmi_scan_pdt page 3
[ 2.216436] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1001
[ 2.217431] rmi4_physical rmi4-00: rmi_read_pdt_entry: F55 V0
[ 2.217442] rmi4_physical rmi4-00: Initializing F55.
[ 2.224189] rmi4_f55 rmi4-00.fn55: F55 num_rx_electrodes: 48 (raw 60)
[ 2.224201] rmi4_f55 rmi4-00.fn55: F55 num_tx_electrodes: 30 (raw 36)
[ 2.224220] rmi4_physical rmi4-00: Registered F55.
[ 2.224231] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 995
[ 2.224889] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
[ 2.224900] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
[ 2.224911] rmi4_physical rmi4-00: rmi_scan_pdt page 4
[ 2.224921] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1257
[ 2.225915] rmi4_physical rmi4-00: rmi_read_pdt_entry: F51 V1
[ 2.225927] rmi4_physical rmi4-00: Initializing F51.
[ 2.226005] rmi4_physical rmi4-00: Registered F51.
[ 2.226016] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1251
[ 2.226677] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
[ 2.226689] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
[ 2.226699] rmi4_physical rmi4-00: rmi_scan_pdt page 5
On Thu, 2016-10-20 at 23:51 +0100, Nick Dyer wrote:
> On Mon, Oct 17, 2016 at 02:30:08PM -0700, Guenter Roeck wrote:
> >
> > On Fri, Sep 30, 2016 at 08:22:47PM -0700, Guenter Roeck wrote:
> > >
> > > Sensor tuning support is needed to determine the number of
> > > enabled
> > > tx and rx electrodes for use in F54 functions.
> > >
> > > The number of enabled electrodes is not identical to the total
> > > number
> > > of electrodes as reported with F55:Query0 and F55:Query1. It has
> > > to be
> > > calculated by analyzing F55:Ctrl1 (sensor receiver assignment)
> > > and
> > > F55:Ctrl2 (sensor transmitter assignment).
> > >
> > > Support for additional sensor tuning functions may be added
> > > later.
> > >
> > > Signed-off-by: Guenter Roeck <[email protected]>
> >
> > Ping ... any comments on this patch and on
> > https://patchwork.kernel.org/patch/9359061/ ?
> >
> > Both patches now apply to mainline.
> >
> > Thanks,
> > Guenter
>
> Hi Guenter-
>
> I've reviewed and tested (on S7300 and S7813) both these patches now
> - you can add my sign-off.
>
> However, on the S7813 firmware, F55 is on PDT page 3, and nothing
> on page 2, so the default behaviour of the mainline driver means it
> is
> not initialised.
>
> So I think we need to revert this change in mainline:
> https://patchwork.kernel.org/patch/3796971/
>
> See below the PDT scan with it reverted and some debug added.
>
> Christopher/Andrew: is there a better heuristic than scanning all 255
> pages, given that some firmwares contain gaps?
It's difficult to say. It is against the RMI4 spec for there to be
gaps in the pages - you're supposed to be able to scan until you hit a
page with an empty PDT, and then stop.
Since F55 is hardcoded to page 3 for this firmware, it may be a
customer specific deviation. This may have been done to accommodate a
customer-written driver that did not scan the PDT, but instead always
looked for F55 on page 3. This idea is supported by the existence of
the F51 custom function on page 4, since F51 almost always requires
customer driver code to handle it.
In my opinion, the Non-standard bit should have been set in the PDT to
indicate that special handling was required, but that wasn't done in
this case.
Anyway, given that this sort of thing has escaped into the wild, I'm
unsure what to advise. Just off the top of my head, one possibility is
to have a "keep-going" option to scan the first 128 pages (0x00 through
0x7F), regardless of whether an empty page is encountered. This could
be triggered either by a product ID on the "known goofy list", or by a
boot/load time flag. I'm sure there are other possibilities, though.
Cheers,
Chris
>
> cheers
>
> Nick
>
> [ 2.181199] rmi4_physical rmi4-00: Creating functions.
> [ 2.181210] rmi4_physical rmi4-00: rmi_scan_pdt page 0
> [ 2.181221] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 233
> [ 2.182218] rmi4_physical rmi4-00: rmi_read_pdt_entry: F34 V2
> [ 2.182230] rmi4_physical rmi4-00: Initializing F34.
> [ 2.182325] rmi4_physical rmi4-00: Registered F34.
> [ 2.182337] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 227
> [ 2.183003] rmi4_physical rmi4-00: rmi_read_pdt_entry: F01 V0
> [ 2.183014] rmi4_physical rmi4-00: Initializing F01.
> [ 2.187358] rmi4_f01 rmi4-00.fn01: found RMI device, manufacturer:
> Synaptics, product: s7813, fw id: 2174259
> [ 2.198822] rmi4_physical rmi4-00: Registered F01.
> [ 2.198834] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 221
> [ 2.199494] rmi4_physical rmi4-00: rmi_read_pdt_entry: F12 V0
> [ 2.199505] rmi4_physical rmi4-00: Initializing F12.
> [ 2.199612] rmi4_f12 rmi4-00.fn12: rmi_f12_probe
> [ 2.210721] rmi4_physical rmi4-00: Registered F12.
> [ 2.210732] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 215
> [ 2.211393] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [ 2.211404] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [ 2.211414] rmi4_physical rmi4-00: rmi_scan_pdt page 1
> [ 2.211424] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 489
> [ 2.212419] rmi4_physical rmi4-00: rmi_read_pdt_entry: F54 V0
> [ 2.212431] rmi4_physical rmi4-00: Initializing F54.
> [ 2.214241] rmi4_f54 rmi4-00.fn54: F54 num_rx_electrodes: 60
> [ 2.214253] rmi4_f54 rmi4-00.fn54: F54 num_tx_electrodes: 36
> [ 2.214263] rmi4_f54 rmi4-00.fn54: F54 capabilities: 0x44
> [ 2.214274] rmi4_f54 rmi4-00.fn54: F54 clock rate: 0x5aa0
> [ 2.214283] rmi4_f54 rmi4-00.fn54: F54 family: 0x2
> [ 2.214695] rmi4_physical rmi4-00: Registered F54.
> [ 2.214708] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 483
> [ 2.215372] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [ 2.215384] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [ 2.215395] rmi4_physical rmi4-00: rmi_scan_pdt page 2
> [ 2.215405] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 745
> [ 2.216404] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [ 2.216415] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [ 2.216426] rmi4_physical rmi4-00: rmi_scan_pdt page 3
> [ 2.216436] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1001
> [ 2.217431] rmi4_physical rmi4-00: rmi_read_pdt_entry: F55 V0
> [ 2.217442] rmi4_physical rmi4-00: Initializing F55.
> [ 2.224189] rmi4_f55 rmi4-00.fn55: F55 num_rx_electrodes: 48 (raw
> 60)
> [ 2.224201] rmi4_f55 rmi4-00.fn55: F55 num_tx_electrodes: 30 (raw
> 36)
> [ 2.224220] rmi4_physical rmi4-00: Registered F55.
> [ 2.224231] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 995
> [ 2.224889] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [ 2.224900] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [ 2.224911] rmi4_physical rmi4-00: rmi_scan_pdt page 4
> [ 2.224921] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1257
> [ 2.225915] rmi4_physical rmi4-00: rmi_read_pdt_entry: F51 V1
> [ 2.225927] rmi4_physical rmi4-00: Initializing F51.
> [ 2.226005] rmi4_physical rmi4-00: Registered F51.
> [ 2.226016] rmi4_physical rmi4-00: rmi_scan_pdt_page addr 1251
> [ 2.226677] rmi4_physical rmi4-00: rmi_read_pdt_entry: F00 V0
> [ 2.226689] rmi4_physical rmi4-00: rmi_scan_pdt_page end of page
> [ 2.226699] rmi4_physical rmi4-00: rmi_scan_pdt page 5
On Thu, Oct 20, 2016 at 04:28:39PM -0700, Christopher Heiny wrote:
> On Thu, 2016-10-20 at 23:51 +0100, Nick Dyer wrote:
> > On Mon, Oct 17, 2016 at 02:30:08PM -0700, Guenter Roeck wrote:
> > >
> > > On Fri, Sep 30, 2016 at 08:22:47PM -0700, Guenter Roeck wrote:
> > > >
> > > > Sensor tuning support is needed to determine the number of
> > > > enabled
> > > > tx and rx electrodes for use in F54 functions.
> > > >
> > > > The number of enabled electrodes is not identical to the total
> > > > number
> > > > of electrodes as reported with F55:Query0 and F55:Query1. It has
> > > > to be
> > > > calculated by analyzing F55:Ctrl1 (sensor receiver assignment)
> > > > and
> > > > F55:Ctrl2 (sensor transmitter assignment).
> > > >
> > > > Support for additional sensor tuning functions may be added
> > > > later.
> > > >
> > > > Signed-off-by: Guenter Roeck <[email protected]>
> > >
> > > Ping ... any comments on this patch and on
> > > https://patchwork.kernel.org/patch/9359061/ ?
> > >
> > > Both patches now apply to mainline.
> > >
> > > Thanks,
> > > Guenter
> >
> > Hi Guenter-
> >
> > I've reviewed and tested (on S7300 and S7813) both these patches now
> > - you can add my sign-off.
> >
> > However, on the S7813 firmware, F55 is on PDT page 3, and nothing
> > on page 2, so the default behaviour of the mainline driver means it
> > is
> > not initialised.
> >
> > So I think we need to revert this change in mainline:
> > https://patchwork.kernel.org/patch/3796971/
> >
> > See below the PDT scan with it reverted and some debug added.
> >
> > Christopher/Andrew: is there a better heuristic than scanning all 255
> > pages, given that some firmwares contain gaps?
>
> It's difficult to say. ?It is against the RMI4 spec for there to be
> gaps in the pages - you're supposed to be able to scan until you hit a
> page with an empty PDT, and then stop.
>
> Since F55 is hardcoded to page 3 for this firmware, it may be a
> customer specific deviation. ?This may have been done to accommodate a
> customer-written driver that did not scan the PDT, but instead always
> looked for F55 on page 3. ?This idea is supported by the existence of
> the F51 custom function on page 4, since F51 almost always requires
> customer driver code to handle it.
>
> In my opinion, the Non-standard bit should have been set in the PDT to
> indicate that special handling was required, but that wasn't done in
> this case.
>
> Anyway, given that this sort of thing has escaped into the wild, I'm
> unsure what to advise. ?Just off the top of my head, one possibility is
> to have a "keep-going" option to scan the first 128 pages (0x00 through
> 0x7F), regardless of whether an empty page is encountered. ?This could
> be triggered either by a product ID on the "known goofy list", or by a
> boot/load time flag. ?I'm sure there are other possibilities, though.
>
Maybe introduce quirks if the problematic device and/or problematic firmware
version can be identified ? Not sure if scanning 128 pages would be necessary,
though - requiring two empty pages to stop scanning might be sufficient.
Guenter