| Message ID | 1313632629-23603-4-git-send-email-jj_ding@emc.com.tw (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Aug 18, 2011 at 9:57 AM, JJ Ding <jj_ding@emc.com.tw> wrote: > For v2 hardware, there is no real parity check, but we can still check > some constant bits for data integrity. > > Signed-off-by: JJ Ding <jj_ding@emc.com.tw> > --- > drivers/input/mouse/elantech.c | 26 +++++++++++++++++++++++--- > 1 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c > index cf41f23..032181c 100644 > --- a/drivers/input/mouse/elantech.c > +++ b/drivers/input/mouse/elantech.c > @@ -376,6 +376,25 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) > etd->parity[packet[3]] == p3; > } > > +static int packet_simple_check_v2(struct psmouse *psmouse) > +{ > + struct elantech_data *etd = psmouse->private; > + unsigned char *packet = psmouse->packet; > + > + if (etd->reports_pressure) > + return (packet[0] & 0x0c) == 0x04 && > + (packet[3] & 0x0f) == 0x02; > + > + if ((packet[0] & 0xc0) == 0x80) > + return (packet[0] & 0x0c) == 0x0c && > + (packet[3] & 0x0e) == 0x08; > + > + return (packet[0] & 0x3c) == 0x3c && > + (packet[1] & 0xf0) == 0x00 && > + (packet[3] & 0x3e) == 0x38 && > + (packet[4] & 0xf0) == 0x00; > +} > + > /* > * Process byte stream from mouse and handle complete packets > */ > @@ -398,7 +417,9 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse) > break; > > case 2: > - /* We don't know how to check parity in protocol v2 */ > + if (etd->paritycheck && !packet_simple_check_v2(psmouse)) > + return PSMOUSE_BAD_DATA; > + > elantech_report_absolute_v2(psmouse); > break; > } > @@ -799,8 +820,7 @@ int elantech_init(struct psmouse *psmouse) > etd->hw_version = 2; > /* For now show extra debug information */ > etd->debug = 1; > - /* Don't know how to do parity checking for version 2 */ > - etd->paritycheck = 0; > + etd->paritycheck = 1; If we always do some sort of check, can we just remove etd->paritycheck now? > > if (etd->fw_version >= 0x020800) > etd->reports_pressure = true; > -- > 1.7.4.1 > > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Aug 18, 2011 at 09:57:06AM +0800, JJ Ding wrote: > For v2 hardware, there is no real parity check, but we can still check > some constant bits for data integrity. > > Signed-off-by: JJ Ding <jj_ding@emc.com.tw> > --- > drivers/input/mouse/elantech.c | 26 +++++++++++++++++++++++--- > 1 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c > index cf41f23..032181c 100644 > --- a/drivers/input/mouse/elantech.c > +++ b/drivers/input/mouse/elantech.c > @@ -376,6 +376,25 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) > etd->parity[packet[3]] == p3; > } > > +static int packet_simple_check_v2(struct psmouse *psmouse) > +{ > + struct elantech_data *etd = psmouse->private; > + unsigned char *packet = psmouse->packet; > + > + if (etd->reports_pressure) > + return (packet[0] & 0x0c) == 0x04 && > + (packet[3] & 0x0f) == 0x02; > + > + if ((packet[0] & 0xc0) == 0x80) > + return (packet[0] & 0x0c) == 0x0c && > + (packet[3] & 0x0e) == 0x08; > + > + return (packet[0] & 0x3c) == 0x3c && > + (packet[1] & 0xf0) == 0x00 && > + (packet[3] & 0x3e) == 0x38 && > + (packet[4] & 0xf0) == 0x00; Can we please spell out the assumptions under which we decide that packet is invalid? Thanks.
Hi Dmitry, On Wed, 17 Aug 2011 23:38:18 -0700, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > On Thu, Aug 18, 2011 at 09:57:06AM +0800, JJ Ding wrote: > > For v2 hardware, there is no real parity check, but we can still check > > some constant bits for data integrity. > > > > Signed-off-by: JJ Ding <jj_ding@emc.com.tw> > > --- > > drivers/input/mouse/elantech.c | 26 +++++++++++++++++++++++--- > > 1 files changed, 23 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c > > index cf41f23..032181c 100644 > > --- a/drivers/input/mouse/elantech.c > > +++ b/drivers/input/mouse/elantech.c > > @@ -376,6 +376,25 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) > > etd->parity[packet[3]] == p3; > > } > > > > +static int packet_simple_check_v2(struct psmouse *psmouse) > > +{ > > + struct elantech_data *etd = psmouse->private; > > + unsigned char *packet = psmouse->packet; > > + > > + if (etd->reports_pressure) > > + return (packet[0] & 0x0c) == 0x04 && > > + (packet[3] & 0x0f) == 0x02; this is for newer v2 hardware > > + > > + if ((packet[0] & 0xc0) == 0x80) > > + return (packet[0] & 0x0c) == 0x0c && > > + (packet[3] & 0x0e) == 0x08; this is for older v2, two finger touch > > + > > + return (packet[0] & 0x3c) == 0x3c && > > + (packet[1] & 0xf0) == 0x00 && > > + (packet[3] & 0x3e) == 0x38 && > > + (packet[4] & 0xf0) == 0x00; this is for older v2, 1/3 finger touch > > Can we please spell out the assumptions under which we decide that > packet is invalid? > > Thanks. > > -- > Dmitry V2 hardware has two flavors. Older ones that do not report pressure, and newer ones that reports pressure and width. With newer ones, all packets (1, 2, 3 finger touch) have the same constant bits. With older ones, 1/3 finger touch packets and 2 finger touch packets have different constant bits. With all three cases, if the constant bits are not exactly what I expected, I consider them invalid. Dmitry, how do you want me to improve this? not enough comments? Thanks jj > -- > To unsubscribe from this list: send the line "unsubscribe linux-input" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Aug 18, 2011 at 03:31:27PM +0800, JJ Ding wrote: > Hi Dmitry, > > On Wed, 17 Aug 2011 23:38:18 -0700, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > > On Thu, Aug 18, 2011 at 09:57:06AM +0800, JJ Ding wrote: > > > For v2 hardware, there is no real parity check, but we can still check > > > some constant bits for data integrity. > > > > > > Signed-off-by: JJ Ding <jj_ding@emc.com.tw> > > > --- > > > drivers/input/mouse/elantech.c | 26 +++++++++++++++++++++++--- > > > 1 files changed, 23 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c > > > index cf41f23..032181c 100644 > > > --- a/drivers/input/mouse/elantech.c > > > +++ b/drivers/input/mouse/elantech.c > > > @@ -376,6 +376,25 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) > > > etd->parity[packet[3]] == p3; > > > } > > > > > > +static int packet_simple_check_v2(struct psmouse *psmouse) > > > +{ > > > + struct elantech_data *etd = psmouse->private; > > > + unsigned char *packet = psmouse->packet; > > > + > > > + if (etd->reports_pressure) > > > + return (packet[0] & 0x0c) == 0x04 && > > > + (packet[3] & 0x0f) == 0x02; > this is for newer v2 hardware > > > > + > > > + if ((packet[0] & 0xc0) == 0x80) > > > + return (packet[0] & 0x0c) == 0x0c && > > > + (packet[3] & 0x0e) == 0x08; > this is for older v2, two finger touch > > > > + > > > + return (packet[0] & 0x3c) == 0x3c && > > > + (packet[1] & 0xf0) == 0x00 && > > > + (packet[3] & 0x3e) == 0x38 && > > > + (packet[4] & 0xf0) == 0x00; > this is for older v2, 1/3 finger touch > > > > > Can we please spell out the assumptions under which we decide that > > packet is invalid? > > > > Thanks. > > > > -- > > Dmitry > V2 hardware has two flavors. Older ones that do not report pressure, > and newer ones that reports pressure and width. > > With newer ones, all packets (1, 2, 3 finger touch) have the same > constant bits. > > With older ones, 1/3 finger touch packets and 2 finger touch packets have > different constant bits. > > With all three cases, if the constant bits are not exactly what I > expected, I consider them invalid. > > Dmitry, how do you want me to improve this? not enough comments? Right, if you could put the above into comments right in the packet_simple_check_v2() that woudl be great. Thanks.
Hi Dmitry, On Thu, 18 Aug 2011 00:52:26 -0700, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > On Thu, Aug 18, 2011 at 03:31:27PM +0800, JJ Ding wrote: > > Hi Dmitry, > > > > On Wed, 17 Aug 2011 23:38:18 -0700, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > > > On Thu, Aug 18, 2011 at 09:57:06AM +0800, JJ Ding wrote: > > > > For v2 hardware, there is no real parity check, but we can still check > > > > some constant bits for data integrity. > > > > > > > > Signed-off-by: JJ Ding <jj_ding@emc.com.tw> > > > > --- > > > > drivers/input/mouse/elantech.c | 26 +++++++++++++++++++++++--- > > > > 1 files changed, 23 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c > > > > index cf41f23..032181c 100644 > > > > --- a/drivers/input/mouse/elantech.c > > > > +++ b/drivers/input/mouse/elantech.c > > > > @@ -376,6 +376,25 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) > > > > etd->parity[packet[3]] == p3; > > > > } > > > > > > > > +static int packet_simple_check_v2(struct psmouse *psmouse) > > > > +{ > > > > + struct elantech_data *etd = psmouse->private; > > > > + unsigned char *packet = psmouse->packet; > > > > + > > > > + if (etd->reports_pressure) > > > > + return (packet[0] & 0x0c) == 0x04 && > > > > + (packet[3] & 0x0f) == 0x02; > > this is for newer v2 hardware > > > > > > + > > > > + if ((packet[0] & 0xc0) == 0x80) > > > > + return (packet[0] & 0x0c) == 0x0c && > > > > + (packet[3] & 0x0e) == 0x08; > > this is for older v2, two finger touch > > > > > > + > > > > + return (packet[0] & 0x3c) == 0x3c && > > > > + (packet[1] & 0xf0) == 0x00 && > > > > + (packet[3] & 0x3e) == 0x38 && > > > > + (packet[4] & 0xf0) == 0x00; > > this is for older v2, 1/3 finger touch > > > > > > > > Can we please spell out the assumptions under which we decide that > > > packet is invalid? > > > > > > Thanks. > > > > > > -- > > > Dmitry > > V2 hardware has two flavors. Older ones that do not report pressure, > > and newer ones that reports pressure and width. > > > > With newer ones, all packets (1, 2, 3 finger touch) have the same > > constant bits. > > > > With older ones, 1/3 finger touch packets and 2 finger touch packets have > > different constant bits. > > > > With all three cases, if the constant bits are not exactly what I > > expected, I consider them invalid. > > > > Dmitry, how do you want me to improve this? not enough comments? > > Right, if you could put the above into comments right in the > packet_simple_check_v2() that woudl be great. > > Thanks. No problem. I will do that. > -- > Dmitry > -- > To unsubscribe from this list: send the line "unsubscribe linux-input" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Op 18-08-11 03:57, JJ Ding schreef: > For v2 hardware, there is no real parity check, but we can still check > some constant bits for data integrity. > > Signed-off-by: JJ Ding<jj_ding@emc.com.tw> If you add some comments, as suggest by Dmitry, it looks perfect :-) Signed-off-by: Éric Piel <eric.piel@tremplin-utc.net> Éric > --- > drivers/input/mouse/elantech.c | 26 +++++++++++++++++++++++--- > 1 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c > index cf41f23..032181c 100644 > --- a/drivers/input/mouse/elantech.c > +++ b/drivers/input/mouse/elantech.c > @@ -376,6 +376,25 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) > etd->parity[packet[3]] == p3; > } > > +static int packet_simple_check_v2(struct psmouse *psmouse) > +{ > + struct elantech_data *etd = psmouse->private; > + unsigned char *packet = psmouse->packet; > + > + if (etd->reports_pressure) > + return (packet[0]& 0x0c) == 0x04&& > + (packet[3]& 0x0f) == 0x02; > + > + if ((packet[0]& 0xc0) == 0x80) > + return (packet[0]& 0x0c) == 0x0c&& > + (packet[3]& 0x0e) == 0x08; > + > + return (packet[0]& 0x3c) == 0x3c&& > + (packet[1]& 0xf0) == 0x00&& > + (packet[3]& 0x3e) == 0x38&& > + (packet[4]& 0xf0) == 0x00; > +} > + > /* > * Process byte stream from mouse and handle complete packets > */ > @@ -398,7 +417,9 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse) > break; > > case 2: > - /* We don't know how to check parity in protocol v2 */ > + if (etd->paritycheck&& !packet_simple_check_v2(psmouse)) > + return PSMOUSE_BAD_DATA; > + > elantech_report_absolute_v2(psmouse); > break; > } > @@ -799,8 +820,7 @@ int elantech_init(struct psmouse *psmouse) > etd->hw_version = 2; > /* For now show extra debug information */ > etd->debug = 1; > - /* Don't know how to do parity checking for version 2 */ > - etd->paritycheck = 0; > + etd->paritycheck = 1; > > if (etd->fw_version>= 0x020800) > etd->reports_pressure = true; -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index cf41f23..032181c 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -376,6 +376,25 @@ static int elantech_check_parity_v1(struct psmouse *psmouse) etd->parity[packet[3]] == p3; } +static int packet_simple_check_v2(struct psmouse *psmouse) +{ + struct elantech_data *etd = psmouse->private; + unsigned char *packet = psmouse->packet; + + if (etd->reports_pressure) + return (packet[0] & 0x0c) == 0x04 && + (packet[3] & 0x0f) == 0x02; + + if ((packet[0] & 0xc0) == 0x80) + return (packet[0] & 0x0c) == 0x0c && + (packet[3] & 0x0e) == 0x08; + + return (packet[0] & 0x3c) == 0x3c && + (packet[1] & 0xf0) == 0x00 && + (packet[3] & 0x3e) == 0x38 && + (packet[4] & 0xf0) == 0x00; +} + /* * Process byte stream from mouse and handle complete packets */ @@ -398,7 +417,9 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse) break; case 2: - /* We don't know how to check parity in protocol v2 */ + if (etd->paritycheck && !packet_simple_check_v2(psmouse)) + return PSMOUSE_BAD_DATA; + elantech_report_absolute_v2(psmouse); break; } @@ -799,8 +820,7 @@ int elantech_init(struct psmouse *psmouse) etd->hw_version = 2; /* For now show extra debug information */ etd->debug = 1; - /* Don't know how to do parity checking for version 2 */ - etd->paritycheck = 0; + etd->paritycheck = 1; if (etd->fw_version >= 0x020800) etd->reports_pressure = true;
For v2 hardware, there is no real parity check, but we can still check some constant bits for data integrity. Signed-off-by: JJ Ding <jj_ding@emc.com.tw> --- drivers/input/mouse/elantech.c | 26 +++++++++++++++++++++++--- 1 files changed, 23 insertions(+), 3 deletions(-)