RE: [PATCH] Input: elantech - support new touchpad IC and extend elan's touchapd command Origianl ic-body field is not sufficient for upcoming IC, Elan ps/2 driver extend the fomation to support future IC. Signed-off-by: KT Liao <kt.liao@xxxxxxxxxx>

From: 廖崇榮
Date: Mon Aug 07 2017 - 10:23:22 EST


Hi Ulrik,
Thanks your review, I add comment in below.

-----Original Message-----
From: ulrik.debie-os@xxxxxxxxx [mailto:ulrik.debie-os@xxxxxxxxx]
Sent: Friday, August 04, 2017 4:52 AM
To: KT Liao
Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-input@xxxxxxxxxxxxxxx;
dmitry.torokhov@xxxxxxxxx; phoenix@xxxxxxxxxx
Subject: Re: [PATCH] Input: elantech - support new touchpad IC and extend
elan's touchapd command Origianl ic-body field is not sufficient for
upcoming IC, Elan ps/2 driver extend the fomation to support future IC.
Signed-off-by: KT Liao <kt.liao@xxxxxxxxxx>

Hi,

Something went wrong with your subject line, it also includes the further
commit message lines and the signed off line ..

Origianl -> Original
fomation .. Do you mean information ?
[KT]:Fix typo and subject line in next patch
On Wed, Aug 02, 2017 at 07:11:41PM +0800, KT Liao wrote:
>
> ---
> drivers/input/mouse/elantech.c | 28 ++++++++++++++++++++++++----
> drivers/input/mouse/elantech.h | 3 +++
> 2 files changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/input/mouse/elantech.c
> b/drivers/input/mouse/elantech.c index 65c9de3..14ab5ba 100644
> --- a/drivers/input/mouse/elantech.c
> +++ b/drivers/input/mouse/elantech.c
> @@ -1398,6 +1398,10 @@ static bool elantech_is_signature_valid(const
unsigned char *param)
> param[2] < 40)
> return true;
>
> + /* hw_version 0x0F does not need to check rate alose*/

Drop the word also:
[KT] : OK

/* hw_version 0x0F does not need to check rate */

> + if ((param[0] & 0x0f) == 0x0f)
> + return true;
> +
> for (i = 0; i < ARRAY_SIZE(rates); i++)
> if (param[2] == rates[i])
> return false;
> @@ -1576,7 +1580,7 @@ static const struct dmi_system_id
> no_hw_res_dmi_table[] = {
> /*
> * determine hardware version and set some properties according to it.
> */
> -static int elantech_set_properties(struct elantech_data *etd)
> +static int elantech_set_properties(struct elantech_data *etd, struct
> +psmouse *psmouse)

Isn't the line too long for this one ?

> {
> /* This represents the version of IC body. */
> int ver = (etd->fw_version & 0x0f0000) >> 16; @@ -1593,14 +1597,14
> @@ static int elantech_set_properties(struct elantech_data *etd)
> case 5:
> etd->hw_version = 3;
> break;
> - case 6 ... 14:
> + case 6 ... 15:
> etd->hw_version = 4;
> break;
> default:
> return -1;
> }
> }

Remove this tab on a line alone you added below ..
[KT]:OK

> -
> +
> /* decide which send_cmd we're gonna use early */
> etd->send_cmd = etd->hw_version >= 3 ? elantech_send_cmd :
> synaptics_send_cmd;
I would propose to place the lines below (up to the end of function
elantech_set_properties) in elantech_init instead of
elantech_set_properties.
[KT]: OK, it's better to move my part to elantech_init and skip psmouse
parameter.


> @@ -1634,6 +1638,22 @@ static int elantech_set_properties(struct
elantech_data *etd)
> /* Enable real hardware resolution on hw_version 3 ? */
> etd->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);
>
> + /*if ver == 15 and info_pattern == 0x01, it is ELAN new pattern
> + *which support a command for extend IC_body/FW_Version reading
> + */
> + etd->info_pattern = etd->fw_version & 0xFF;
> + if (ver == 0x0F && etd->info_pattern == 0x01) {
I really appreciate the message that is given in the comment.
Why would you store the lowest byte of fw_version once more as an int .. and
use it only once at exactly the next line ..

Alternatives I see are:
1) Merge the two lines (so there is no info_pattern anymore)
2) Use a local variable info_pattern to store it intermediately
3) Have some macro that basically takes the lowest byte (I can't immediately
find a good example for this one)
[KT] I will use a local UCHAR info_pattern for it .

> + if (etd->send_cmd(psmouse, ETP_ICBODY_QUERY, etd->icbody)) {
> + psmouse_err(psmouse, "failed to query icbody
data\n");
> + return -1;
> + }
> + psmouse_info(psmouse,
> + "Elan ICBODY query result %02x, %02x,
%02x\n",
> + etd->icbody[0], etd->icbody[1],
etd->icbody[2]);
> + etd->fw_version &= 0xFFFF00;
> + etd->fw_version |= etd->icbody[2];

Brr, this throws away information. Is icbody2 really meant to replace bottom
byte of fw_version ? I see no benefit of doing this ! I would propose to
drop the above 2 lines that alter fw_version.
[KT] icbody2 will be the real fw version in upcoming HW, it's only useful
when we really need to check it.
>From vendor's view, original etd->fw_version is not fw-versoin. It contain
many information in it.

I agree with your point that some information is not useful now.
How about that if I only modify below part this time to support new IC, I
think it's simple and won't cause confuse.
> - case 6 ... 14:
> + case 6 ... 15:

And add more information reading once we really need it in future patch.
Please let me know you thought. thanks

> + }
> +
> return 0;
> }
>
> @@ -1667,7 +1687,7 @@ int elantech_init(struct psmouse *psmouse)
> }
> etd->fw_version = (param[0] << 16) | (param[1] << 8) | param[2];
>
> - if (elantech_set_properties(etd)) {
> + if (elantech_set_properties(etd, psmouse)) {

When those lines are moved to elantech_init, you don't need to add the
psmouse paramater.

> psmouse_err(psmouse, "unknown hardware version,
aborting...\n");
> goto init_fail;
> }
> diff --git a/drivers/input/mouse/elantech.h
> b/drivers/input/mouse/elantech.h index e1cbf40..708ad85 100644
> --- a/drivers/input/mouse/elantech.h
> +++ b/drivers/input/mouse/elantech.h
> @@ -21,6 +21,7 @@
> #define ETP_CAPABILITIES_QUERY 0x02
> #define ETP_SAMPLE_QUERY 0x03
> #define ETP_RESOLUTION_QUERY 0x04
> +#define ETP_ICBODY_QUERY 0x05
>
> /*
> * Command values for register reading or writing @@ -130,6 +131,7 @@
> struct elantech_data {
> unsigned char debug;
> unsigned char capabilities[3];
> unsigned char samples[3];
> + unsigned char icbody[3];
> bool paritycheck;
> bool jumpy_cursor;
> bool reports_pressure;
> @@ -140,6 +142,7 @@ struct elantech_data {
> unsigned int single_finger_reports;
> unsigned int y_max;
> unsigned int width;
> + unsigned int info_pattern;

So I would propose to remove this one.

> struct finger_pos mt[ETP_MAX_FINGERS];
> unsigned char parity[256];
> int (*send_cmd)(struct psmouse *psmouse, unsigned char c, unsigned
> char *param);
> --
> 2.7.4

Kind regards,
Ulrik