Re: [PATCH] HSI: cmt_speech: fix timestamp interface

From: Thomas Gleixner
Date: Thu Apr 23 2015 - 09:37:52 EST


On Thu, 16 Apr 2015, Sebastian Reichel wrote:

> The user interface for timestamps in the new cmt_speech
> driver is broken in multiple ways:
>
> - The layout is incompatible between 32-bit and 64-bit user
> space, because of the size differences in 'struct timespec'.
> This means that the driver can not work when used with 32-bit
> user space on a 64-bit kernel.
>
> - As there are plans to change 32-bit user space to use
> a 64-bit time_t type in the future, it will also be
> incompatible with new 32-bit user space.
>
> To keep support for the user space tools written for this driver (which
> have lived many years out-of-tree), the interface has been hardened to
> unsigned 32-bit values.
>
> Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>
> ---
> drivers/hsi/clients/cmt_speech.c | 9 +++++++--
> include/uapi/linux/hsi/cs-protocol.h | 16 +++++++++++-----
> 2 files changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/hsi/clients/cmt_speech.c b/drivers/hsi/clients/cmt_speech.c
> index 4983529..67aef3f 100644
> --- a/drivers/hsi/clients/cmt_speech.c
> +++ b/drivers/hsi/clients/cmt_speech.c
> @@ -451,9 +451,14 @@ static void cs_hsi_read_on_control_complete(struct hsi_msg *msg)
> dev_dbg(&hi->cl->device, "Read on control: %08X\n", cmd);
> cs_release_cmd(msg);
> if (hi->flags & CS_FEAT_TSTAMP_RX_CTRL) {
> - struct timespec *tstamp =
> + struct timespec tspec;
> + struct cs_timestamp *tstamp =
> &hi->mmap_cfg->tstamp_rx_ctrl;
> - do_posix_clock_monotonic_gettime(tstamp);
> +
> + do_posix_clock_monotonic_gettime(&tspec);

Can you please use ktime_get_ts() instead of
do_posix_clock_monotonic_gettime(). I'm desperately trying to get rid
of the latter, but it seems to come back in circles.

Thanks,

tglx
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