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@xxxxxxxxx>
>>> ---
>>> 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);
>>
