From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mout.kundenserver.de ([212.227.17.10]:59062 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751838AbdK0NZy (ORCPT ); Mon, 27 Nov 2017 08:25:54 -0500 From: Arnd Bergmann To: Steve Longerbeam , Philipp Zabel , Mauro Carvalho Chehab , Greg Kroah-Hartman Cc: y2038@lists.linaro.org, Arnd Bergmann , Hans Verkuil , Russell King , linux-media@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: [PATCH 8/8] [media] staging: imx: use ktime_t for timestamps Date: Mon, 27 Nov 2017 14:20:00 +0100 Message-Id: <20171127132027.1734806-8-arnd@arndb.de> In-Reply-To: <20171127132027.1734806-1-arnd@arndb.de> References: <20171127132027.1734806-1-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: The imx media driver passes around monotonic timestamps in the deprecated 'timespec' format. This is not a problem for the driver, as they won't overflow, but moving to either timespec64 or ktime_t is preferred. I'm picking ktime_t for simplicity here. frame_interval_monitor() is the main function that changes, as it tries to compare a time interval in microseconds. The algorithm slightly changes here, to avoid 64-bit division. The code previously assumed that the error was at most 32-bit worth of microseconds here, so I'm making the same assumption but add an explicit test for it. Signed-off-by: Arnd Bergmann --- drivers/staging/media/imx/imx-media-csi.c | 8 ++------ drivers/staging/media/imx/imx-media-fim.c | 30 +++++++++++++++++------------- drivers/staging/media/imx/imx-media.h | 2 +- 3 files changed, 20 insertions(+), 20 deletions(-) diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c index bb1d6dafca83..26994b429cf2 100644 --- a/drivers/staging/media/imx/imx-media-csi.c +++ b/drivers/staging/media/imx/imx-media-csi.c @@ -207,13 +207,9 @@ static irqreturn_t csi_idmac_eof_interrupt(int irq, void *dev_id) goto unlock; } - if (priv->fim) { - struct timespec cur_ts; - - ktime_get_ts(&cur_ts); + if (priv->fim) /* call frame interval monitor */ - imx_media_fim_eof_monitor(priv->fim, &cur_ts); - } + imx_media_fim_eof_monitor(priv->fim, ktime_get()); csi_vb2_buf_done(priv); diff --git a/drivers/staging/media/imx/imx-media-fim.c b/drivers/staging/media/imx/imx-media-fim.c index 47275ef803f3..6df189135db8 100644 --- a/drivers/staging/media/imx/imx-media-fim.c +++ b/drivers/staging/media/imx/imx-media-fim.c @@ -66,7 +66,7 @@ struct imx_media_fim { int icap_flags; int counter; - struct timespec last_ts; + ktime_t last_ts; unsigned long sum; /* usec */ unsigned long nominal; /* usec */ @@ -147,22 +147,26 @@ static void send_fim_event(struct imx_media_fim *fim, unsigned long error) * (presumably random) interrupt latency. */ static void frame_interval_monitor(struct imx_media_fim *fim, - struct timespec *ts) + ktime_t timestamp) { - unsigned long interval, error, error_avg; + long long interval, error; + unsigned long error_avg; bool send_event = false; - struct timespec diff; if (!fim->enabled || ++fim->counter <= 0) goto out_update_ts; - diff = timespec_sub(*ts, fim->last_ts); - interval = diff.tv_sec * 1000 * 1000 + diff.tv_nsec / 1000; - error = abs(interval - fim->nominal); + /* max error is less than l00µs, so use 32-bit division or fail */ + interval = ktime_to_ns(ktime_sub(timestamp, fim->last_ts)); + error = abs(interval - NSEC_PER_USEC * (u64)fim->nominal); + if (error > U32_MAX) + error = U32_MAX; + else + error = abs((u32)error / NSEC_PER_USEC); if (fim->tolerance_max && error >= fim->tolerance_max) { dev_dbg(fim->sd->dev, - "FIM: %lu ignored, out of tolerance bounds\n", + "FIM: %llu ignored, out of tolerance bounds\n", error); fim->counter--; goto out_update_ts; @@ -184,7 +188,7 @@ static void frame_interval_monitor(struct imx_media_fim *fim, } out_update_ts: - fim->last_ts = *ts; + fim->last_ts = timestamp; if (send_event) send_fim_event(fim, error_avg); } @@ -195,14 +199,14 @@ static void frame_interval_monitor(struct imx_media_fim *fim, * to interrupt latency. */ static void fim_input_capture_handler(int channel, void *dev_id, - struct timespec *ts) + ktime_t timestamp) { struct imx_media_fim *fim = dev_id; unsigned long flags; spin_lock_irqsave(&fim->lock, flags); - frame_interval_monitor(fim, ts); + frame_interval_monitor(fim, timestamp); if (!completion_done(&fim->icap_first_event)) complete(&fim->icap_first_event); @@ -405,14 +409,14 @@ static int init_fim_controls(struct imx_media_fim *fim) * the frame_interval_monitor() is called by the input capture event * callback handler in that case. */ -void imx_media_fim_eof_monitor(struct imx_media_fim *fim, struct timespec *ts) +void imx_media_fim_eof_monitor(struct imx_media_fim *fim, ktime_t timestamp) { unsigned long flags; spin_lock_irqsave(&fim->lock, flags); if (!icap_enabled(fim)) - frame_interval_monitor(fim, ts); + frame_interval_monitor(fim, timestamp); spin_unlock_irqrestore(&fim->lock, flags); } diff --git a/drivers/staging/media/imx/imx-media.h b/drivers/staging/media/imx/imx-media.h index d409170632bd..ac3ab115394f 100644 --- a/drivers/staging/media/imx/imx-media.h +++ b/drivers/staging/media/imx/imx-media.h @@ -280,7 +280,7 @@ int imx_media_pipeline_set_stream(struct imx_media_dev *imxmd, /* imx-media-fim.c */ struct imx_media_fim; -void imx_media_fim_eof_monitor(struct imx_media_fim *fim, struct timespec *ts); +void imx_media_fim_eof_monitor(struct imx_media_fim *fim, ktime_t timestamp); int imx_media_fim_set_stream(struct imx_media_fim *fim, const struct v4l2_fract *frame_interval, bool on); -- 2.9.0