Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
23.01.2021 01:37, Michał Mirosław пишет: > On Fri, Jan 22, 2021 at 11:10:52PM +0300, Dmitry Osipenko wrote: >> 08.01.2021 01:06, Dmitry Osipenko пишет: >>> 11.12.2020 21:48, Dmitry Torokhov пишет: On Fri, Dec 11, 2020 at 06:04:01PM +0100, Michał Mirosław wrote: > On Fri, Dec 11, 2020 at 07:39:33PM +0300, Dmitry Osipenko wrote: >> 11.12.2020 19:09, Michał Mirosław пишет: >>> On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: Hi Michał, On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: > @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, > void *_dev) > } > > report_len = ts->buf[FW_HDR_LENGTH] / > report_count; > - if (report_len != PACKET_SIZE) { > + if (report_len != PACKET_SIZE && > + report_len != PACKET_SIZE_OLD) { > dev_err(>dev, > - "mismatching report length: > %*ph\n", > + "unsupported report length: > %*ph\n", > HEADER_SIZE, ts->buf); Do I understand this correctly that the old packets are only observed on EKTF3624? If so can we expand the check so that we only accept packets with "old" size when we know we are dealing with this device? >>> >>> We only have EKTF3624 and can't be sure there are no other chips >>> needing this. >> >> In practice this older packet format should be seen only on 3624, but >> nevertheless we could make it more explicit by adding the extra chip_id >> checks. >> >> It won't be difficult to change it in the future if will be needed. >> >> I think the main point that Dmitry Torokhov conveys here is that we >> should minimize the possible impact on the current EKT3500 code since we >> don't have definitive answers regarding the firmware differences among >> the hardware variants. > > The only possible impact here is that older firmware instead of breaking > would suddenly work. Maybe we can accept such a risk? These are not controllers we'll randomly find in devices: Windows boxes use I2C HID, Chrome devices use "new" firmware, so that leaves random ARM where someone needs to consciously add proper compatible before the driver will engage with the controller. I would prefer we were conservative and not accept potentially invalid data. Thanks. >>> >>> Michał, will you be able to make v9 with all the review comments addressed? >>> >> >> I'll make a v9 over this weekend. >> >> Michał, please let me know if you already started to work on this or >> have any objections. > > Hi, > > Sorry for staying quiet so long. I have to revive my Transformer before > I can test anything, so please go ahead. No problems, hope it's nothing serious and you'll have some spare time to revive it soon!
Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
On Fri, Jan 22, 2021 at 11:10:52PM +0300, Dmitry Osipenko wrote: > 08.01.2021 01:06, Dmitry Osipenko пишет: > > 11.12.2020 21:48, Dmitry Torokhov пишет: > >> On Fri, Dec 11, 2020 at 06:04:01PM +0100, Michał Mirosław wrote: > >>> On Fri, Dec 11, 2020 at 07:39:33PM +0300, Dmitry Osipenko wrote: > 11.12.2020 19:09, Michał Mirosław пишет: > > On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: > >> Hi Michał, > >> On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: > >>> @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, > >>> void *_dev) > >>> } > >>> > >>> report_len = ts->buf[FW_HDR_LENGTH] / > >>> report_count; > >>> - if (report_len != PACKET_SIZE) { > >>> + if (report_len != PACKET_SIZE && > >>> + report_len != PACKET_SIZE_OLD) { > >>> dev_err(>dev, > >>> - "mismatching report length: > >>> %*ph\n", > >>> + "unsupported report length: > >>> %*ph\n", > >>> HEADER_SIZE, ts->buf); > >> Do I understand this correctly that the old packets are only observed > >> on > >> EKTF3624? If so can we expand the check so that we only accept packets > >> with "old" size when we know we are dealing with this device? > > > > We only have EKTF3624 and can't be sure there are no other chips > > needing this. > > In practice this older packet format should be seen only on 3624, but > nevertheless we could make it more explicit by adding the extra chip_id > checks. > > It won't be difficult to change it in the future if will be needed. > > I think the main point that Dmitry Torokhov conveys here is that we > should minimize the possible impact on the current EKT3500 code since we > don't have definitive answers regarding the firmware differences among > the hardware variants. > >>> > >>> The only possible impact here is that older firmware instead of breaking > >>> would suddenly work. Maybe we can accept such a risk? > >> > >> These are not controllers we'll randomly find in devices: Windows boxes > >> use I2C HID, Chrome devices use "new" firmware, so that leaves random > >> ARM where someone needs to consciously add proper compatible before the > >> driver will engage with the controller. > >> > >> I would prefer we were conservative and not accept potentially invalid > >> data. > >> > >> Thanks. > >> > > > > Michał, will you be able to make v9 with all the review comments addressed? > > > > I'll make a v9 over this weekend. > > Michał, please let me know if you already started to work on this or > have any objections. Hi, Sorry for staying quiet so long. I have to revive my Transformer before I can test anything, so please go ahead. Best Regards Michał Mirosław
Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
08.01.2021 01:06, Dmitry Osipenko пишет: > 11.12.2020 21:48, Dmitry Torokhov пишет: >> On Fri, Dec 11, 2020 at 06:04:01PM +0100, Michał Mirosław wrote: >>> On Fri, Dec 11, 2020 at 07:39:33PM +0300, Dmitry Osipenko wrote: 11.12.2020 19:09, Michał Mirosław пишет: > On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: >> Hi Michał, >> On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: >>> @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, void >>> *_dev) >>> } >>> >>> report_len = ts->buf[FW_HDR_LENGTH] / >>> report_count; >>> - if (report_len != PACKET_SIZE) { >>> + if (report_len != PACKET_SIZE && >>> + report_len != PACKET_SIZE_OLD) { >>> dev_err(>dev, >>> - "mismatching report length: >>> %*ph\n", >>> + "unsupported report length: >>> %*ph\n", >>> HEADER_SIZE, ts->buf); >> Do I understand this correctly that the old packets are only observed on >> EKTF3624? If so can we expand the check so that we only accept packets >> with "old" size when we know we are dealing with this device? > > We only have EKTF3624 and can't be sure there are no other chips needing > this. In practice this older packet format should be seen only on 3624, but nevertheless we could make it more explicit by adding the extra chip_id checks. It won't be difficult to change it in the future if will be needed. I think the main point that Dmitry Torokhov conveys here is that we should minimize the possible impact on the current EKT3500 code since we don't have definitive answers regarding the firmware differences among the hardware variants. >>> >>> The only possible impact here is that older firmware instead of breaking >>> would suddenly work. Maybe we can accept such a risk? >> >> These are not controllers we'll randomly find in devices: Windows boxes >> use I2C HID, Chrome devices use "new" firmware, so that leaves random >> ARM where someone needs to consciously add proper compatible before the >> driver will engage with the controller. >> >> I would prefer we were conservative and not accept potentially invalid >> data. >> >> Thanks. >> > > Michał, will you be able to make v9 with all the review comments addressed? > I'll make a v9 over this weekend. Michał, please let me know if you already started to work on this or have any objections.
Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
11.12.2020 21:48, Dmitry Torokhov пишет: > On Fri, Dec 11, 2020 at 06:04:01PM +0100, Michał Mirosław wrote: >> On Fri, Dec 11, 2020 at 07:39:33PM +0300, Dmitry Osipenko wrote: >>> 11.12.2020 19:09, Michał Mirosław пишет: On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: > Hi Michał, > On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: >> @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, void >> *_dev) >> } >> >> report_len = ts->buf[FW_HDR_LENGTH] / >> report_count; >> -if (report_len != PACKET_SIZE) { >> +if (report_len != PACKET_SIZE && >> +report_len != PACKET_SIZE_OLD) { >> dev_err(>dev, >> -"mismatching report length: >> %*ph\n", >> +"unsupported report length: >> %*ph\n", >> HEADER_SIZE, ts->buf); > Do I understand this correctly that the old packets are only observed on > EKTF3624? If so can we expand the check so that we only accept packets > with "old" size when we know we are dealing with this device? We only have EKTF3624 and can't be sure there are no other chips needing this. >>> >>> In practice this older packet format should be seen only on 3624, but >>> nevertheless we could make it more explicit by adding the extra chip_id >>> checks. >>> >>> It won't be difficult to change it in the future if will be needed. >>> >>> I think the main point that Dmitry Torokhov conveys here is that we >>> should minimize the possible impact on the current EKT3500 code since we >>> don't have definitive answers regarding the firmware differences among >>> the hardware variants. >> >> The only possible impact here is that older firmware instead of breaking >> would suddenly work. Maybe we can accept such a risk? > > These are not controllers we'll randomly find in devices: Windows boxes > use I2C HID, Chrome devices use "new" firmware, so that leaves random > ARM where someone needs to consciously add proper compatible before the > driver will engage with the controller. > > I would prefer we were conservative and not accept potentially invalid > data. > > Thanks. > Michał, will you be able to make v9 with all the review comments addressed?
Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
On Fri, Dec 11, 2020 at 06:04:01PM +0100, Michał Mirosław wrote: > On Fri, Dec 11, 2020 at 07:39:33PM +0300, Dmitry Osipenko wrote: > > 11.12.2020 19:09, Michał Mirosław пишет: > > > On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: > > >> Hi Michał, > > >> On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: > > >>> @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, void > > >>> *_dev) > > >>> } > > >>> > > >>> report_len = ts->buf[FW_HDR_LENGTH] / > > >>> report_count; > > >>> - if (report_len != PACKET_SIZE) { > > >>> + if (report_len != PACKET_SIZE && > > >>> + report_len != PACKET_SIZE_OLD) { > > >>> dev_err(>dev, > > >>> - "mismatching report length: > > >>> %*ph\n", > > >>> + "unsupported report length: > > >>> %*ph\n", > > >>> HEADER_SIZE, ts->buf); > > >> Do I understand this correctly that the old packets are only observed on > > >> EKTF3624? If so can we expand the check so that we only accept packets > > >> with "old" size when we know we are dealing with this device? > > > > > > We only have EKTF3624 and can't be sure there are no other chips needing > > > this. > > > > In practice this older packet format should be seen only on 3624, but > > nevertheless we could make it more explicit by adding the extra chip_id > > checks. > > > > It won't be difficult to change it in the future if will be needed. > > > > I think the main point that Dmitry Torokhov conveys here is that we > > should minimize the possible impact on the current EKT3500 code since we > > don't have definitive answers regarding the firmware differences among > > the hardware variants. > > The only possible impact here is that older firmware instead of breaking > would suddenly work. Maybe we can accept such a risk? These are not controllers we'll randomly find in devices: Windows boxes use I2C HID, Chrome devices use "new" firmware, so that leaves random ARM where someone needs to consciously add proper compatible before the driver will engage with the controller. I would prefer we were conservative and not accept potentially invalid data. Thanks. -- Dmitry
Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
On Fri, Dec 11, 2020 at 07:39:33PM +0300, Dmitry Osipenko wrote: > 11.12.2020 19:09, Michał Mirosław пишет: > > On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: > >> Hi Michał, > >> On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: > >>> @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, void > >>> *_dev) > >>> } > >>> > >>> report_len = ts->buf[FW_HDR_LENGTH] / report_count; > >>> - if (report_len != PACKET_SIZE) { > >>> + if (report_len != PACKET_SIZE && > >>> + report_len != PACKET_SIZE_OLD) { > >>> dev_err(>dev, > >>> - "mismatching report length: %*ph\n", > >>> + "unsupported report length: %*ph\n", > >>> HEADER_SIZE, ts->buf); > >> Do I understand this correctly that the old packets are only observed on > >> EKTF3624? If so can we expand the check so that we only accept packets > >> with "old" size when we know we are dealing with this device? > > > > We only have EKTF3624 and can't be sure there are no other chips needing > > this. > > In practice this older packet format should be seen only on 3624, but > nevertheless we could make it more explicit by adding the extra chip_id > checks. > > It won't be difficult to change it in the future if will be needed. > > I think the main point that Dmitry Torokhov conveys here is that we > should minimize the possible impact on the current EKT3500 code since we > don't have definitive answers regarding the firmware differences among > the hardware variants. The only possible impact here is that older firmware instead of breaking would suddenly work. Maybe we can accept such a risk? Best Regards Michał Mirosław
Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
11.12.2020 19:09, Michał Mirosław пишет: > On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: >> Hi Michał, >> On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: >>> @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, void >>> *_dev) >>> } >>> >>> report_len = ts->buf[FW_HDR_LENGTH] / report_count; >>> - if (report_len != PACKET_SIZE) { >>> + if (report_len != PACKET_SIZE && >>> + report_len != PACKET_SIZE_OLD) { >>> dev_err(>dev, >>> - "mismatching report length: %*ph\n", >>> + "unsupported report length: %*ph\n", >>> HEADER_SIZE, ts->buf); >> Do I understand this correctly that the old packets are only observed on >> EKTF3624? If so can we expand the check so that we only accept packets >> with "old" size when we know we are dealing with this device? > > We only have EKTF3624 and can't be sure there are no other chips needing this. In practice this older packet format should be seen only on 3624, but nevertheless we could make it more explicit by adding the extra chip_id checks. It won't be difficult to change it in the future if will be needed. I think the main point that Dmitry Torokhov conveys here is that we should minimize the possible impact on the current EKT3500 code since we don't have definitive answers regarding the firmware differences among the hardware variants.
Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
On Thu, Dec 10, 2020 at 11:29:40PM -0800, Dmitry Torokhov wrote: > Hi Michał, > On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: > > @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, void > > *_dev) > > } > > > > report_len = ts->buf[FW_HDR_LENGTH] / report_count; > > - if (report_len != PACKET_SIZE) { > > + if (report_len != PACKET_SIZE && > > + report_len != PACKET_SIZE_OLD) { > > dev_err(>dev, > > - "mismatching report length: %*ph\n", > > + "unsupported report length: %*ph\n", > > HEADER_SIZE, ts->buf); > Do I understand this correctly that the old packets are only observed on > EKTF3624? If so can we expand the check so that we only accept packets > with "old" size when we know we are dealing with this device? We only have EKTF3624 and can't be sure there are no other chips needing this. Best Regards Michał Mirosław
Re: [PATCH RESEND v8 2/4] input: elants: support old touch report format
Hi Michał, On Fri, Dec 11, 2020 at 07:53:56AM +0100, Michał Mirosław wrote: > @@ -998,17 +1011,18 @@ static irqreturn_t elants_i2c_irq(int irq, void *_dev) > } > > report_len = ts->buf[FW_HDR_LENGTH] / report_count; > - if (report_len != PACKET_SIZE) { > + if (report_len != PACKET_SIZE && > + report_len != PACKET_SIZE_OLD) { > dev_err(>dev, > - "mismatching report length: %*ph\n", > + "unsupported report length: %*ph\n", > HEADER_SIZE, ts->buf); Do I understand this correctly that the old packets are only observed on EKTF3624? If so can we expand the check so that we only accept packets with "old" size when we know we are dealing with this device? Thanks. -- Dmitry