Re: [PATCH] Input: elantech - Add a special mode for a specific FW The touchapd which sample ver is 0x74 and hw_version is 0x03 have a fw bug which will cause crush sometimes, I add some work-around for it and our customer ask us to upstream the patch Signed-off-by: KT Liao <kt.liao@emc.com.tw>

ulrik.debie-os
2016-12-02T22:30:08Z

Hi,

Thank you for the patch, see below my feedback on your patch.
Can you provide the contents of fw_verison, capabilities and samples ?

It this fw bug present on multiple laptops ?

On Fri, Dec 02, 2016 at 01:59:17PM +0800, KT Liao wrote:
> Date: Fri, 2 Dec 2016 13:59:17 +0800
> From: KT Liao <kt.liao@emc.com.tw>
> To: linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
> dmitry.torokhov@gmail.com
> Cc: phoenix@emc.com.tw, kt.liao@emc.com.tw
> Subject: [PATCH] Input: elantech - Add a special mode for a specific FW The
> touchapd which sample ver is 0x74 and hw_version is 0x03 have a fw bug
> which will cause crush sometimes, I add some work-around for it and our
> customer ask us to upstream the patch Signed-off-by: KT Liao
> <kt.liao@emc.com.tw>

It seems that the newlines got lost when you used git-send-email. The
subject should be a oneliner, the remaining part should go to the mail body.

> X-Mailer: git-send-email 2.7.4
> X-Mailing-List: linux-input@vger.kernel.org
>
> ---
> drivers/input/mouse/elantech.c | 152 +++++++++++++++++++++++++++++++++++------
> 1 file changed, 131 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
> index db7d1d6..acfe7f2 100644
> --- a/drivers/input/mouse/elantech.c
> +++ b/drivers/input/mouse/elantech.c
> @@ -539,6 +539,30 @@ static void elantech_report_absolute_v3(struct psmouse *psmouse,
> input_sync(dev);
> }
>
> +static psmouse_ret_t elantech_report_relative_v3(struct psmouse *psmouse)
> +{
> + struct input_dev *dev = psmouse->dev;
> + unsigned char *packet = psmouse->packet;
> + int rel_x = 0, rel_y = 0;
> +
> + if (psmouse->pktcnt < psmouse->pktsize)
> + return PSMOUSE_GOOD_DATA;

This is a duplicate of elantech_process_byte and you skipped the
elantech_packet_dump feature of elantech_process_byte. I think it would be
better to let elantech_process_byte call this elantech_report_relative_v3
just like all the other reportings.
Is it required to also disable the elantech_packet_check_v3 ?

Can you document the typical packet format for
elantech_report_relative_v3 ? Something similar to elantech_report_trackpoint ?

> +
> + input_report_rel(dev, REL_WHEEL, -(signed char)packet[3]);
> +
> + rel_x = (int) packet[1] - (int) ((packet[0] << 4) & 0x100);
> + rel_y = (int) ((packet[0] << 3) & 0x100) - (int) packet[2];
> +
> + input_report_key(dev, BTN_LEFT, packet[0] & 1);
> + input_report_key(dev, BTN_RIGHT, (packet[0] >> 1) & 1);
> + input_report_rel(dev, REL_X, rel_x);
> + input_report_rel(dev, REL_Y, rel_y);
> +
> + input_sync(dev);
> +
> + return PSMOUSE_FULL_PACKET;
> +}
> +
> static void elantech_input_sync_v4(struct psmouse *psmouse)
> {
> struct input_dev *dev = psmouse->dev;
> @@ -696,14 +720,14 @@ static int elantech_packet_check_v1(struct psmouse *psmouse)
>
> static int elantech_debounce_check_v2(struct psmouse *psmouse)
> {
> - /*
> - * When we encounter packet that matches this exactly, it means the
> - * hardware is in debounce status. Just ignore the whole packet.
> - */
> - const u8 debounce_packet[] = { 0x84, 0xff, 0xff, 0x02, 0xff, 0xff };
> - unsigned char *packet = psmouse->packet;
> -
> - return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
> + /*
> + * When we encounter packet that matches this exactly, it means the
> + * hardware is in debounce status. Just ignore the whole packet.
> + */
> + const u8 debounce_packet[] = { 0x84, 0xff, 0xff, 0x02, 0xff, 0xff };
> + unsigned char *packet = psmouse->packet;
> +
> + return !memcmp(packet, debounce_packet, sizeof(debounce_packet));
> }

Confirmed, the lines of elantech_debounce_check_v2 do not start with tab
but spaces, but preferably this will be part of a separate commit.

>
> static int elantech_packet_check_v2(struct psmouse *psmouse)
> @@ -995,6 +1019,29 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
> return rc;
> }
>
> +/* it's the work around mode for some touchpad which has FW bug, but dont' support IAP funciton */

This line is too long, split it across multiple lines.

> +static int elantech_set_special_mode(struct psmouse *psmouse)
> +{
> + unsigned char param[3];
> + int rc = 0;

Knowing Dmitry, he would prefer to have error as name instead of rc.

> +
> + param[0] = 0xc8;
> + param[1] = 0x64;
> + param[2] = 0x50;
> +
> + if (elantech_ps2_command(psmouse, &param[0], PSMOUSE_CMD_SETRATE) ||
> + elantech_ps2_command(psmouse, &param[1], PSMOUSE_CMD_SETRATE) ||
> + elantech_ps2_command(psmouse, &param[2], PSMOUSE_CMD_SETRATE) ||
> + elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETID)) {
> + rc = -1;
> + }

Hm, these do look very similar to intellimouse_detect. Is that a coincidence ?

> +
> + psmouse->set_rate(psmouse, 0x64);
> + psmouse->set_resolution(psmouse, 200);

Why hardcode set_rate and set_resolution when they are already module
parameters with the defaults exactly the ones selected here.

> +
> + return rc;
> +}
> +
> static int elantech_set_range(struct psmouse *psmouse,
> unsigned int *x_min, unsigned int *y_min,
> unsigned int *x_max, unsigned int *y_max,
> @@ -1279,6 +1326,32 @@ static int elantech_set_input_params(struct psmouse *psmouse)
> return 0;
> }
>
> +static int elantech_set_input_params_special(struct psmouse *psmouse)
> +{
> + struct input_dev *dev = psmouse->dev;
> + struct elantech_data *etd = psmouse->private;
> + unsigned int x_min = 0, y_min = 0, x_max = 0, y_max = 0, width = 0;
> +
> + if (elantech_set_range(psmouse, &x_min, &y_min, &x_max, &y_max, &width))
> + return -1;
> +
> + __set_bit(INPUT_PROP_POINTER, dev->propbit);
> + __set_bit(EV_KEY, dev->evbit);
> +
> + __set_bit(BTN_LEFT, dev->keybit);
> + __set_bit(BTN_RIGHT, dev->keybit);
> +
> + __set_bit(EV_REL, dev->evbit);
> + __set_bit(REL_X, dev->relbit);
> + __set_bit(REL_Y, dev->relbit);
> + __set_bit(REL_WHEEL, dev->relbit);
> +
> + etd->y_max = y_max;
> + etd->width = width;
> +
> + return 0;
> +}
> +
> struct elantech_attr_data {
> size_t field_offset;
> unsigned char reg;
> @@ -1483,15 +1556,28 @@ static void elantech_disconnect(struct psmouse *psmouse)
> */
> static int elantech_reconnect(struct psmouse *psmouse)
> {
> +
> + struct elantech_data *etd = psmouse->private;
> +
> psmouse_reset(psmouse);
>
> if (elantech_detect(psmouse, 0))
> return -1;
>
> - if (elantech_set_absolute_mode(psmouse)) {
> - psmouse_err(psmouse,
> - "failed to put touchpad back into absolute mode.\n");
> - return -1;
> + if (etd->samples[1] == 0x74 && etd->hw_version == 0x03) {

Is this the appropriate way to detect only the devices that have this
special OTP FW ? Any chance that other elantech devices will also be
falsely detected for this special mode ?

> + /* handle specail FW issue */

Typo .. special instead of specail.

> + psmouse_info(psmouse, "ELANTECH special OTP FW detected and call special handle\n");
> + if (elantech_set_special_mode(psmouse)) {
> + psmouse_err(psmouse,
> + "failed to put touchpad back into special mode.\n");
> + return -1;
> + }
> + } else {
> + if (elantech_set_absolute_mode(psmouse)) {
> + psmouse_err(psmouse,
> + "failed to put touchpad back into absolute mode.\n");
> + return -1;
> + }
> }
>
> return 0;
> @@ -1687,10 +1773,20 @@ int elantech_init(struct psmouse *psmouse)
> etd->samples[0], etd->samples[1], etd->samples[2]);
> }
>
> - if (elantech_set_absolute_mode(psmouse)) {
> - psmouse_err(psmouse,
> - "failed to put touchpad into absolute mode.\n");
> - goto init_fail;
> + if (etd->samples[1] == 0x74 && etd->hw_version == 0x03) {

See above in elantech_reconnect for same line.

> + /* handle specail FW issue */

Typo .. special instead of specail.

> + psmouse_info(psmouse, "ELANTECH special OTP FW detected and call special handle\n");
> + if (elantech_set_special_mode(psmouse)) {
> + psmouse_err(psmouse,
> + "failed to put touchpad back into special mode.\n");
> + return -1;
> + }
> + } else {
> + if (elantech_set_absolute_mode(psmouse)) {
> + psmouse_err(psmouse,
> + "failed to put touchpad back into absolute mode.\n");
> + return -1;
> + }
> }
>
> if (etd->fw_version == 0x381f17) {
> @@ -1698,9 +1794,17 @@ int elantech_init(struct psmouse *psmouse)
> psmouse->set_rate = elantech_set_rate_restore_reg_07;
> }
>
> - if (elantech_set_input_params(psmouse)) {
> - psmouse_err(psmouse, "failed to query touchpad range.\n");
> - goto init_fail;
> +
> + if (etd->samples[1] == 0x74 && etd->hw_version == 0x03) {
> + if (elantech_set_input_params_special(psmouse)) {
> + psmouse_err(psmouse, "failed to query touchpad range for special FW.\n");
> + goto init_fail;
> + }
> + } else {
> + if (elantech_set_input_params(psmouse)) {
> + psmouse_err(psmouse, "failed to query touchpad range.\n");
> + goto init_fail;
> + }
> }
>
> error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
> @@ -1746,10 +1850,16 @@ int elantech_init(struct psmouse *psmouse)
> goto init_fail_tp_reg;
> }
>
> - psmouse->protocol_handler = elantech_process_byte;
> psmouse->disconnect = elantech_disconnect;
> psmouse->reconnect = elantech_reconnect;
> - psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
> +
> + if (etd->samples[1] == 0x74 && etd->hw_version == 0x03) {
> + psmouse->protocol_handler = elantech_report_relative_v3;
> + psmouse->pktsize = 4;
> + } else {
> + psmouse->protocol_handler = elantech_process_byte;
> + psmouse->pktsize = etd->hw_version > 1 ? 6 : 4;
> + }

Preferably do the split between elantech_report_relative_v3 and elantech_report_absolute_v3 in elantech_process_byte and not here.

>
> return 0;
> init_fail_tp_reg:
> --
> 2.7.4

Thank you,
Kind regards,
Ulrik De Bie