media: staging/intel-ipu3: reduce kernel stack usage

The imgu_css_queue structure is too large to be put on the kernel
stack, as we can see in 32-bit builds:

drivers/staging/media/ipu3/ipu3-css.c: In function 'imgu_css_fmt_try':
drivers/staging/media/ipu3/ipu3-css.c:1863:1: error: the frame size of 1172 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

By dynamically allocating this array, the stack usage goes down to an
acceptable 140 bytes for the same x86-32 configuration.

Fixes: f5f2e4273518 ("media: staging/intel-ipu3: Add css pipeline programming")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Cao, Bingbu <bingbu.cao@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/staging/media/ipu3/ipu3-css.c b/drivers/staging/media/ipu3/ipu3-css.c
index 15ab77e4b766a9796a7c89f578978393df84062f..e7f1898874fd46767aecef830fcbe6eb47562b7d 100644 (file)
--- a/drivers/staging/media/ipu3/ipu3-css.c
+++ b/drivers/staging/media/ipu3/ipu3-css.c
@@ -3,6 +3,7 @@
 
 #include <linux/device.h>
 #include <linux/iopoll.h>
+#include <linux/slab.h>
 
 #include "ipu3-css.h"
 #include "ipu3-css-fw.h"
@@ -1744,15 +1745,18 @@ int imgu_css_fmt_try(struct imgu_css *css,
        struct v4l2_rect *const bds = &r[IPU3_CSS_RECT_BDS];
        struct v4l2_rect *const env = &r[IPU3_CSS_RECT_ENVELOPE];
        struct v4l2_rect *const gdc = &r[IPU3_CSS_RECT_GDC];
-       struct imgu_css_queue q[IPU3_CSS_QUEUES];
-       struct v4l2_pix_format_mplane *const in =
-                                       &q[IPU3_CSS_QUEUE_IN].fmt.mpix;
-       struct v4l2_pix_format_mplane *const out =
-                                       &q[IPU3_CSS_QUEUE_OUT].fmt.mpix;
-       struct v4l2_pix_format_mplane *const vf =
-                                       &q[IPU3_CSS_QUEUE_VF].fmt.mpix;
+       struct imgu_css_queue *q;
+       struct v4l2_pix_format_mplane *in, *out, *vf;
        int i, s, ret;
 
+       q = kcalloc(IPU3_CSS_QUEUES, sizeof(struct imgu_css_queue), GFP_KERNEL);
+       if (!q)
+               return -ENOMEM;
+
+       in  = &q[IPU3_CSS_QUEUE_IN].fmt.mpix;
+       out = &q[IPU3_CSS_QUEUE_OUT].fmt.mpix;
+       vf  = &q[IPU3_CSS_QUEUE_VF].fmt.mpix;
+
        /* Adjust all formats, get statistics buffer sizes and formats */
        for (i = 0; i < IPU3_CSS_QUEUES; i++) {
                if (fmts[i])
@@ -1766,7 +1770,8 @@ int imgu_css_fmt_try(struct imgu_css *css,
                                        IPU3_CSS_QUEUE_TO_FLAGS(i))) {
                        dev_notice(css->dev, "can not initialize queue %s\n",
                                   qnames[i]);
-                       return -EINVAL;
+                       ret = -EINVAL;
+                       goto out;
                }
        }
        for (i = 0; i < IPU3_CSS_RECTS; i++) {
@@ -1788,7 +1793,8 @@ int imgu_css_fmt_try(struct imgu_css *css,
        if (!imgu_css_queue_enabled(&q[IPU3_CSS_QUEUE_IN]) ||
            !imgu_css_queue_enabled(&q[IPU3_CSS_QUEUE_OUT])) {
                dev_warn(css->dev, "required queues are disabled\n");
-               return -EINVAL;
+               ret = -EINVAL;
+               goto out;
        }
 
        if (!imgu_css_queue_enabled(&q[IPU3_CSS_QUEUE_OUT])) {
@@ -1829,7 +1835,8 @@ int imgu_css_fmt_try(struct imgu_css *css,
        ret = imgu_css_find_binary(css, pipe, q, r);
        if (ret < 0) {
                dev_err(css->dev, "failed to find suitable binary\n");
-               return -EINVAL;
+               ret = -EINVAL;
+               goto out;
        }
        css->pipes[pipe].bindex = ret;
 
@@ -1843,7 +1850,8 @@ int imgu_css_fmt_try(struct imgu_css *css,
                                                IPU3_CSS_QUEUE_TO_FLAGS(i))) {
                                dev_err(css->dev,
                                        "final resolution adjustment failed\n");
-                               return -EINVAL;
+                               ret = -EINVAL;
+                               goto out;
                        }
                        *fmts[i] = q[i].fmt.mpix;
                }
@@ -1859,7 +1867,10 @@ int imgu_css_fmt_try(struct imgu_css *css,
                 bds->width, bds->height, gdc->width, gdc->height,
                 out->width, out->height, vf->width, vf->height);
 
-       return 0;
+       ret = 0;
+out:
+       kfree(q);
+       return ret;
 }
 
 int imgu_css_fmt_set(struct imgu_css *css,