| Message ID | 20241214191421.94172-4-vassilisamir@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | iio: mark scan_timestamp as __private | expand |
On 12/14/24 1:14 PM, Vasileios Amoiridis wrote: > Drop conditional in favor of always calculating the timestamp value. > This simplifies the code and allows to drop usage of internal private > variable "scan_timestamp" of the struct iio_dev. > > Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com> > --- > drivers/iio/common/ssp_sensors/ssp_iio.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/drivers/iio/common/ssp_sensors/ssp_iio.c b/drivers/iio/common/ssp_sensors/ssp_iio.c > index caa404edd9d0..6b86b5315694 100644 > --- a/drivers/iio/common/ssp_sensors/ssp_iio.c > +++ b/drivers/iio/common/ssp_sensors/ssp_iio.c > @@ -8,6 +8,8 @@ > #include <linux/iio/kfifo_buf.h> > #include <linux/module.h> > #include <linux/slab.h> > +#include <linux/unaligned.h> > +#include <linux/units.h> > #include "ssp_iio_sensor.h" > > /** > @@ -70,7 +72,6 @@ EXPORT_SYMBOL_NS(ssp_common_buffer_postdisable, "IIO_SSP_SENSORS"); > int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, > unsigned int len, int64_t timestamp) > { > - __le32 time; > int64_t calculated_time = 0; > struct ssp_sensor_data *spd = iio_priv(indio_dev); > > @@ -82,11 +83,7 @@ int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, > */ > memcpy(spd->buffer, buf, len); > > - if (indio_dev->scan_timestamp) { > - memcpy(&time, &((char *)buf)[len], SSP_TIME_SIZE); > - calculated_time = > - timestamp + (int64_t)le32_to_cpu(time) * 1000000; > - } > + calculated_time = timestamp + get_unaligned_le32(buf + len) * MEGA; Don't we still need to cast to 64 bit to avoid multiplication overflow? > > return iio_push_to_buffers_with_timestamp(indio_dev, spd->buffer, > calculated_time);
On Mon, Dec 16, 2024 at 03:57:44PM -0600, David Lechner wrote: > On 12/14/24 1:14 PM, Vasileios Amoiridis wrote: > > Drop conditional in favor of always calculating the timestamp value. > > This simplifies the code and allows to drop usage of internal private > > variable "scan_timestamp" of the struct iio_dev. > > > > Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com> > > --- > > drivers/iio/common/ssp_sensors/ssp_iio.c | 9 +++------ > > 1 file changed, 3 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/iio/common/ssp_sensors/ssp_iio.c b/drivers/iio/common/ssp_sensors/ssp_iio.c > > index caa404edd9d0..6b86b5315694 100644 > > --- a/drivers/iio/common/ssp_sensors/ssp_iio.c > > +++ b/drivers/iio/common/ssp_sensors/ssp_iio.c > > @@ -8,6 +8,8 @@ > > #include <linux/iio/kfifo_buf.h> > > #include <linux/module.h> > > #include <linux/slab.h> > > +#include <linux/unaligned.h> > > +#include <linux/units.h> > > #include "ssp_iio_sensor.h" > > > > /** > > @@ -70,7 +72,6 @@ EXPORT_SYMBOL_NS(ssp_common_buffer_postdisable, "IIO_SSP_SENSORS"); > > int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, > > unsigned int len, int64_t timestamp) > > { > > - __le32 time; > > int64_t calculated_time = 0; > > struct ssp_sensor_data *spd = iio_priv(indio_dev); > > > > @@ -82,11 +83,7 @@ int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, > > */ > > memcpy(spd->buffer, buf, len); > > > > - if (indio_dev->scan_timestamp) { > > - memcpy(&time, &((char *)buf)[len], SSP_TIME_SIZE); > > - calculated_time = > > - timestamp + (int64_t)le32_to_cpu(time) * 1000000; > > - } > > + calculated_time = timestamp + get_unaligned_le32(buf + len) * MEGA; > > Don't we still need to cast to 64 bit to avoid multiplication overflow? > Hi David, Thanks for your message! Aren't we already covered by the fact that MEGA is defined as an unsigned long? include/linux/units.h:12:#define MEGA 1000000UL Cheers, Vasilis > > > > return iio_push_to_buffers_with_timestamp(indio_dev, spd->buffer, > > calculated_time); >
On 12/17/24 5:41 PM, Vasileios Amoiridis wrote: > On Mon, Dec 16, 2024 at 03:57:44PM -0600, David Lechner wrote: >> On 12/14/24 1:14 PM, Vasileios Amoiridis wrote: >>> Drop conditional in favor of always calculating the timestamp value. >>> This simplifies the code and allows to drop usage of internal private >>> variable "scan_timestamp" of the struct iio_dev. >>> >>> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com> >>> --- >>> drivers/iio/common/ssp_sensors/ssp_iio.c | 9 +++------ >>> 1 file changed, 3 insertions(+), 6 deletions(-) >>> >>> diff --git a/drivers/iio/common/ssp_sensors/ssp_iio.c b/drivers/iio/common/ssp_sensors/ssp_iio.c >>> index caa404edd9d0..6b86b5315694 100644 >>> --- a/drivers/iio/common/ssp_sensors/ssp_iio.c >>> +++ b/drivers/iio/common/ssp_sensors/ssp_iio.c >>> @@ -8,6 +8,8 @@ >>> #include <linux/iio/kfifo_buf.h> >>> #include <linux/module.h> >>> #include <linux/slab.h> >>> +#include <linux/unaligned.h> >>> +#include <linux/units.h> >>> #include "ssp_iio_sensor.h" >>> >>> /** >>> @@ -70,7 +72,6 @@ EXPORT_SYMBOL_NS(ssp_common_buffer_postdisable, "IIO_SSP_SENSORS"); >>> int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, >>> unsigned int len, int64_t timestamp) >>> { >>> - __le32 time; >>> int64_t calculated_time = 0; >>> struct ssp_sensor_data *spd = iio_priv(indio_dev); >>> >>> @@ -82,11 +83,7 @@ int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, >>> */ >>> memcpy(spd->buffer, buf, len); >>> >>> - if (indio_dev->scan_timestamp) { >>> - memcpy(&time, &((char *)buf)[len], SSP_TIME_SIZE); >>> - calculated_time = >>> - timestamp + (int64_t)le32_to_cpu(time) * 1000000; >>> - } >>> + calculated_time = timestamp + get_unaligned_le32(buf + len) * MEGA; >> >> Don't we still need to cast to 64 bit to avoid multiplication overflow? >> > > Hi David, > > Thanks for your message! > > Aren't we already covered by the fact that MEGA is defined as an > unsigned long? That is only 64-bits on 64-bit architectures, so could still overflow on 32-bit architectures where long is 32-bit. > > include/linux/units.h:12:#define MEGA 1000000UL > > Cheers, > Vasilis > >>> >>> return iio_push_to_buffers_with_timestamp(indio_dev, spd->buffer, >>> calculated_time); >>
On Wed, Dec 18, 2024 at 09:17:44AM -0600, David Lechner wrote: > On 12/17/24 5:41 PM, Vasileios Amoiridis wrote: > > On Mon, Dec 16, 2024 at 03:57:44PM -0600, David Lechner wrote: > >> On 12/14/24 1:14 PM, Vasileios Amoiridis wrote: > >>> Drop conditional in favor of always calculating the timestamp value. > >>> This simplifies the code and allows to drop usage of internal private > >>> variable "scan_timestamp" of the struct iio_dev. > >>> > >>> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com> > >>> --- > >>> drivers/iio/common/ssp_sensors/ssp_iio.c | 9 +++------ > >>> 1 file changed, 3 insertions(+), 6 deletions(-) > >>> > >>> diff --git a/drivers/iio/common/ssp_sensors/ssp_iio.c b/drivers/iio/common/ssp_sensors/ssp_iio.c > >>> index caa404edd9d0..6b86b5315694 100644 > >>> --- a/drivers/iio/common/ssp_sensors/ssp_iio.c > >>> +++ b/drivers/iio/common/ssp_sensors/ssp_iio.c > >>> @@ -8,6 +8,8 @@ > >>> #include <linux/iio/kfifo_buf.h> > >>> #include <linux/module.h> > >>> #include <linux/slab.h> > >>> +#include <linux/unaligned.h> > >>> +#include <linux/units.h> > >>> #include "ssp_iio_sensor.h" > >>> > >>> /** > >>> @@ -70,7 +72,6 @@ EXPORT_SYMBOL_NS(ssp_common_buffer_postdisable, "IIO_SSP_SENSORS"); > >>> int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, > >>> unsigned int len, int64_t timestamp) > >>> { > >>> - __le32 time; > >>> int64_t calculated_time = 0; > >>> struct ssp_sensor_data *spd = iio_priv(indio_dev); > >>> > >>> @@ -82,11 +83,7 @@ int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, > >>> */ > >>> memcpy(spd->buffer, buf, len); > >>> > >>> - if (indio_dev->scan_timestamp) { > >>> - memcpy(&time, &((char *)buf)[len], SSP_TIME_SIZE); > >>> - calculated_time = > >>> - timestamp + (int64_t)le32_to_cpu(time) * 1000000; > >>> - } > >>> + calculated_time = timestamp + get_unaligned_le32(buf + len) * MEGA; > >> > >> Don't we still need to cast to 64 bit to avoid multiplication overflow? > >> > > > > Hi David, > > > > Thanks for your message! > > > > Aren't we already covered by the fact that MEGA is defined as an > > unsigned long? > > That is only 64-bits on 64-bit architectures, so could still overflow on > 32-bit architectures where long is 32-bit. > Hi David, Hmmm, I think you are right. I can fix it in next, iteration. I will wait also for Jonathan's comments on the rest of the series. Cheers, Vasilis > > > > include/linux/units.h:12:#define MEGA 1000000UL > > > > Cheers, > > Vasilis > > > >>> > >>> return iio_push_to_buffers_with_timestamp(indio_dev, spd->buffer, > >>> calculated_time); > >> >
On Wed, 18 Dec 2024 22:13:55 +0100 Vasileios Amoiridis <vassilisamir@gmail.com> wrote: > On Wed, Dec 18, 2024 at 09:17:44AM -0600, David Lechner wrote: > > On 12/17/24 5:41 PM, Vasileios Amoiridis wrote: > > > On Mon, Dec 16, 2024 at 03:57:44PM -0600, David Lechner wrote: > > >> On 12/14/24 1:14 PM, Vasileios Amoiridis wrote: > > >>> Drop conditional in favor of always calculating the timestamp value. > > >>> This simplifies the code and allows to drop usage of internal private > > >>> variable "scan_timestamp" of the struct iio_dev. > > >>> > > >>> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com> > > >>> --- > > >>> drivers/iio/common/ssp_sensors/ssp_iio.c | 9 +++------ > > >>> 1 file changed, 3 insertions(+), 6 deletions(-) > > >>> > > >>> diff --git a/drivers/iio/common/ssp_sensors/ssp_iio.c b/drivers/iio/common/ssp_sensors/ssp_iio.c > > >>> index caa404edd9d0..6b86b5315694 100644 > > >>> --- a/drivers/iio/common/ssp_sensors/ssp_iio.c > > >>> +++ b/drivers/iio/common/ssp_sensors/ssp_iio.c > > >>> @@ -8,6 +8,8 @@ > > >>> #include <linux/iio/kfifo_buf.h> > > >>> #include <linux/module.h> > > >>> #include <linux/slab.h> > > >>> +#include <linux/unaligned.h> > > >>> +#include <linux/units.h> > > >>> #include "ssp_iio_sensor.h" > > >>> > > >>> /** > > >>> @@ -70,7 +72,6 @@ EXPORT_SYMBOL_NS(ssp_common_buffer_postdisable, "IIO_SSP_SENSORS"); > > >>> int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, > > >>> unsigned int len, int64_t timestamp) > > >>> { > > >>> - __le32 time; > > >>> int64_t calculated_time = 0; > > >>> struct ssp_sensor_data *spd = iio_priv(indio_dev); > > >>> > > >>> @@ -82,11 +83,7 @@ int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, > > >>> */ > > >>> memcpy(spd->buffer, buf, len); > > >>> > > >>> - if (indio_dev->scan_timestamp) { > > >>> - memcpy(&time, &((char *)buf)[len], SSP_TIME_SIZE); > > >>> - calculated_time = > > >>> - timestamp + (int64_t)le32_to_cpu(time) * 1000000; > > >>> - } > > >>> + calculated_time = timestamp + get_unaligned_le32(buf + len) * MEGA; > > >> > > >> Don't we still need to cast to 64 bit to avoid multiplication overflow? > > >> > > > > > > Hi David, > > > > > > Thanks for your message! > > > > > > Aren't we already covered by the fact that MEGA is defined as an > > > unsigned long? > > > > That is only 64-bits on 64-bit architectures, so could still overflow on > > 32-bit architectures where long is 32-bit. > > > > Hi David, > > Hmmm, I think you are right. I can fix it in next, iteration. I will > wait also for Jonathan's comments on the rest of the series. > I tweaked it and applied. Also dropped the initial assignment of calculated_time given it is now always set before use. Thanks, Jonathan > Cheers, > Vasilis > > > > > > > include/linux/units.h:12:#define MEGA 1000000UL > > > > > > Cheers, > > > Vasilis > > > > > >>> > > >>> return iio_push_to_buffers_with_timestamp(indio_dev, spd->buffer, > > >>> calculated_time); > > >> > >
diff --git a/drivers/iio/common/ssp_sensors/ssp_iio.c b/drivers/iio/common/ssp_sensors/ssp_iio.c index caa404edd9d0..6b86b5315694 100644 --- a/drivers/iio/common/ssp_sensors/ssp_iio.c +++ b/drivers/iio/common/ssp_sensors/ssp_iio.c @@ -8,6 +8,8 @@ #include <linux/iio/kfifo_buf.h> #include <linux/module.h> #include <linux/slab.h> +#include <linux/unaligned.h> +#include <linux/units.h> #include "ssp_iio_sensor.h" /** @@ -70,7 +72,6 @@ EXPORT_SYMBOL_NS(ssp_common_buffer_postdisable, "IIO_SSP_SENSORS"); int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, unsigned int len, int64_t timestamp) { - __le32 time; int64_t calculated_time = 0; struct ssp_sensor_data *spd = iio_priv(indio_dev); @@ -82,11 +83,7 @@ int ssp_common_process_data(struct iio_dev *indio_dev, void *buf, */ memcpy(spd->buffer, buf, len); - if (indio_dev->scan_timestamp) { - memcpy(&time, &((char *)buf)[len], SSP_TIME_SIZE); - calculated_time = - timestamp + (int64_t)le32_to_cpu(time) * 1000000; - } + calculated_time = timestamp + get_unaligned_le32(buf + len) * MEGA; return iio_push_to_buffers_with_timestamp(indio_dev, spd->buffer, calculated_time);
Drop conditional in favor of always calculating the timestamp value. This simplifies the code and allows to drop usage of internal private variable "scan_timestamp" of the struct iio_dev. Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com> --- drivers/iio/common/ssp_sensors/ssp_iio.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)