media: staging: atomisp: reduce kernel stack usage

The atomisp_set_fmt() function has multiple copies of the large
v4l2_format structure on its stack, resulting in a warning about
excessive stack usage in some rare randconfig builds.

drivers/staging/media/atomisp/pci/atomisp_cmd.c:5600:5: error: stack frame size of 1084 bytes in function 'atomisp_set_fmt' [-Werror,-Wframe-larger-than=]

Of this structure, only three members in the 'fmt.pix' member are
used, so simplify it by using the smaller v4l2_pix_format structure
directly. This reduces the stack usage to 612 bytes, and it could
be reduced further by only storing the three members that are used.

Link: https://lore.kernel.org/linux-media/20210226140524.3478346-1-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/staging/media/atomisp/pci/atomisp_cmd.c b/drivers/staging/media/atomisp/pci/atomisp_cmd.c
index cc6b3ce05feda368edf0dd10098eebc3ad10aff5..14abc1ca00e8e7c9c899ca693866cbceb7bf951a 100644 (file)
--- a/drivers/staging/media/atomisp/pci/atomisp_cmd.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_cmd.c
@@ -4835,7 +4835,7 @@ static void __atomisp_init_stream_info(u16 stream_index,
 }
 
 /* This function looks up the closest available resolution. */
-int atomisp_try_fmt(struct video_device *vdev, struct v4l2_format *f,
+int atomisp_try_fmt(struct video_device *vdev, struct v4l2_pix_format *f,
                    bool *res_overflow)
 {
        struct atomisp_device *isp = video_get_drvdata(vdev);
@@ -4857,18 +4857,18 @@ int atomisp_try_fmt(struct video_device *vdev, struct v4l2_format *f,
                return -EINVAL;
 
        stream_index = atomisp_source_pad_to_stream_id(asd, source_pad);
-       fmt = atomisp_get_format_bridge(f->fmt.pix.pixelformat);
+       fmt = atomisp_get_format_bridge(f->pixelformat);
        if (!fmt) {
                dev_err(isp->dev, "unsupported pixelformat!\n");
                fmt = atomisp_output_fmts;
        }
 
-       if (f->fmt.pix.width <= 0 || f->fmt.pix.height <= 0)
+       if (f->width <= 0 || f->height <= 0)
                return -EINVAL;
 
        snr_mbus_fmt->code = fmt->mbus_code;
-       snr_mbus_fmt->width = f->fmt.pix.width;
-       snr_mbus_fmt->height = f->fmt.pix.height;
+       snr_mbus_fmt->width = f->width;
+       snr_mbus_fmt->height = f->height;
 
        __atomisp_init_stream_info(stream_index, stream_info);
 
@@ -4890,7 +4890,7 @@ int atomisp_try_fmt(struct video_device *vdev, struct v4l2_format *f,
                return -EINVAL;
        }
 
-       f->fmt.pix.pixelformat = fmt->pixelformat;
+       f->pixelformat = fmt->pixelformat;
 
        /*
         * If the format is jpeg or custom RAW, then the width and height will
@@ -4898,17 +4898,17 @@ int atomisp_try_fmt(struct video_device *vdev, struct v4l2_format *f,
         * the below conditions. So just assign to what is being returned from
         * the sensor driver.
         */
-       if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_JPEG ||
-           f->fmt.pix.pixelformat == V4L2_PIX_FMT_CUSTOM_M10MO_RAW) {
-               f->fmt.pix.width = snr_mbus_fmt->width;
-               f->fmt.pix.height = snr_mbus_fmt->height;
+       if (f->pixelformat == V4L2_PIX_FMT_JPEG ||
+           f->pixelformat == V4L2_PIX_FMT_CUSTOM_M10MO_RAW) {
+               f->width = snr_mbus_fmt->width;
+               f->height = snr_mbus_fmt->height;
                return 0;
        }
 
-       if (snr_mbus_fmt->width < f->fmt.pix.width
-           && snr_mbus_fmt->height < f->fmt.pix.height) {
-               f->fmt.pix.width = snr_mbus_fmt->width;
-               f->fmt.pix.height = snr_mbus_fmt->height;
+       if (snr_mbus_fmt->width < f->width
+           && snr_mbus_fmt->height < f->height) {
+               f->width = snr_mbus_fmt->width;
+               f->height = snr_mbus_fmt->height;
                /* Set the flag when resolution requested is
                 * beyond the max value supported by sensor
                 */
@@ -4917,12 +4917,10 @@ int atomisp_try_fmt(struct video_device *vdev, struct v4l2_format *f,
        }
 
        /* app vs isp */
-       f->fmt.pix.width = rounddown(
-                              clamp_t(u32, f->fmt.pix.width, ATOM_ISP_MIN_WIDTH,
-                                      ATOM_ISP_MAX_WIDTH), ATOM_ISP_STEP_WIDTH);
-       f->fmt.pix.height = rounddown(
-                               clamp_t(u32, f->fmt.pix.height, ATOM_ISP_MIN_HEIGHT,
-                                       ATOM_ISP_MAX_HEIGHT), ATOM_ISP_STEP_HEIGHT);
+       f->width = rounddown(clamp_t(u32, f->width, ATOM_ISP_MIN_WIDTH,
+                                    ATOM_ISP_MAX_WIDTH), ATOM_ISP_STEP_WIDTH);
+       f->height = rounddown(clamp_t(u32, f->height, ATOM_ISP_MIN_HEIGHT,
+                                     ATOM_ISP_MAX_HEIGHT), ATOM_ISP_STEP_HEIGHT);
 
        return 0;
 }
@@ -5461,7 +5459,7 @@ static void atomisp_get_dis_envelop(struct atomisp_sub_device *asd,
 }
 
 static void atomisp_check_copy_mode(struct atomisp_sub_device *asd,
-                                   int source_pad, struct v4l2_format *f)
+                                   int source_pad, struct v4l2_pix_format *f)
 {
 #if defined(ISP2401_NEW_INPUT_SYSTEM)
        struct v4l2_mbus_framefmt *sink, *src;
@@ -5472,8 +5470,8 @@ static void atomisp_check_copy_mode(struct atomisp_sub_device *asd,
                                      V4L2_SUBDEV_FORMAT_ACTIVE, source_pad);
 
        if ((sink->code == src->code &&
-            sink->width == f->fmt.pix.width &&
-            sink->height == f->fmt.pix.height) ||
+            sink->width == f->width &&
+            sink->height == f->height) ||
            ((asd->isp->inputs[asd->input_curr].type == SOC_CAMERA) &&
             (asd->isp->inputs[asd->input_curr].camera_caps->
              sensor[asd->sensor_curr].stream_num > 1)))
@@ -5487,7 +5485,7 @@ static void atomisp_check_copy_mode(struct atomisp_sub_device *asd,
 }
 
 static int atomisp_set_fmt_to_snr(struct video_device *vdev,
-                                 struct v4l2_format *f, unsigned int pixelformat,
+                                 struct v4l2_pix_format *f, unsigned int pixelformat,
                                  unsigned int padding_w, unsigned int padding_h,
                                  unsigned int dvs_env_w, unsigned int dvs_env_h)
 {
@@ -5515,7 +5513,7 @@ static int atomisp_set_fmt_to_snr(struct video_device *vdev,
        if (!format)
                return -EINVAL;
 
-       v4l2_fill_mbus_format(ffmt, &f->fmt.pix, format->mbus_code);
+       v4l2_fill_mbus_format(ffmt, f, format->mbus_code);
        ffmt->height += padding_h + dvs_env_h;
        ffmt->width += padding_w + dvs_env_w;
 
@@ -5585,8 +5583,8 @@ int atomisp_set_fmt(struct video_device *vdev, struct v4l2_format *f)
        const struct atomisp_format_bridge *format_bridge;
        const struct atomisp_format_bridge *snr_format_bridge;
        struct ia_css_frame_info output_info, raw_output_info;
-       struct v4l2_format snr_fmt = *f;
-       struct v4l2_format backup_fmt = *f, s_fmt = *f;
+       struct v4l2_pix_format snr_fmt = f->fmt.pix;
+       struct v4l2_pix_format backup_fmt = snr_fmt, s_fmt;
        unsigned int dvs_env_w = 0, dvs_env_h = 0;
        unsigned int padding_w = pad_w, padding_h = pad_h;
        bool res_overflow = false, crop_needs_override = false;
@@ -5760,11 +5758,10 @@ int atomisp_set_fmt(struct video_device *vdev, struct v4l2_format *f)
                dev_warn(isp->dev, "Try format failed with error %d\n", ret);
                return ret;
        }
-       f->fmt.pix.width = snr_fmt.fmt.pix.width;
-       f->fmt.pix.height = snr_fmt.fmt.pix.height;
+       f->fmt.pix.width = snr_fmt.width;
+       f->fmt.pix.height = snr_fmt.height;
 
-       snr_format_bridge =
-           atomisp_get_format_bridge(snr_fmt.fmt.pix.pixelformat);
+       snr_format_bridge = atomisp_get_format_bridge(snr_fmt.pixelformat);
        if (!snr_format_bridge) {
                dev_warn(isp->dev, "Can't find bridge format\n");
                return -EINVAL;
@@ -5845,11 +5842,11 @@ int atomisp_set_fmt(struct video_device *vdev, struct v4l2_format *f)
                 * and height while set_mbus_fmt() so actual resolutions are
                 * being used in while set media bus format.
                 */
-               s_fmt = *f;
+               s_fmt = f->fmt.pix;
                if (f->fmt.pix.pixelformat == V4L2_PIX_FMT_JPEG ||
                    f->fmt.pix.pixelformat == V4L2_PIX_FMT_CUSTOM_M10MO_RAW) {
-                       s_fmt.fmt.pix.width = backup_fmt.fmt.pix.width;
-                       s_fmt.fmt.pix.height = backup_fmt.fmt.pix.height;
+                       s_fmt.width = backup_fmt.width;
+                       s_fmt.height = backup_fmt.height;
                }
                ret = atomisp_set_fmt_to_snr(vdev, &s_fmt,
                                             f->fmt.pix.pixelformat, padding_w,

diff --git a/drivers/staging/media/atomisp/pci/atomisp_cmd.h b/drivers/staging/media/atomisp/pci/atomisp_cmd.h
index 1c0d464c2ac1d88fca345f5b05efcc0545d2f3e2..412baeb91944952df866a2251ef1463d8bc16137 100644 (file)
--- a/drivers/staging/media/atomisp/pci/atomisp_cmd.h
+++ b/drivers/staging/media/atomisp/pci/atomisp_cmd.h
@@ -333,7 +333,7 @@ int atomisp_get_sensor_mode_data(struct atomisp_sub_device *asd,
 int atomisp_get_fmt(struct video_device *vdev, struct v4l2_format *f);
 
 /* This function looks up the closest available resolution. */
-int atomisp_try_fmt(struct video_device *vdev, struct v4l2_format *f,
+int atomisp_try_fmt(struct video_device *vdev, struct v4l2_pix_format *f,
                    bool *res_overflow);
 
 int atomisp_set_fmt(struct video_device *vdev, struct v4l2_format *f);

diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
index 548d82028bb09e027cb984192ee7a371cc8c1f82..6f5fe509215463c8cec3f9570b8f4ef2b63db801 100644 (file)
--- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
@@ -843,7 +843,7 @@ static int atomisp_try_fmt_cap(struct file *file, void *fh,
        int ret;
 
        rt_mutex_lock(&isp->mutex);
-       ret = atomisp_try_fmt(vdev, f, NULL);
+       ret = atomisp_try_fmt(vdev, &f->fmt.pix, NULL);
        rt_mutex_unlock(&isp->mutex);
        return ret;
 }