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From:   Peter Suti <peter.suti@streamunlimited.com>
To:     chuansheng.liu@intel.com, dan.carpenter@oracle.com,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Javier Martinez Canillas <javierm@redhat.com>
Cc:     Peter Suti <peter.suti@streamunlimited.com>,
        dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
        linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH v2] staging: fbtft: core: set smem_len before fb_deferred_io_init call
Date:   Wed, 27 Jul 2022 09:07:23 +0200
Message-Id: <20220727070723.1489599-1-peter.suti@streamunlimited.com>
In-Reply-To: <20220726161347.GR2338@kadam>
References: <20220726161347.GR2338@kadam>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The fbtft_framebuffer_alloc() calls fb_deferred_io_init() before
initializing info->fix.smem_len.  It is set to zero by the
framebuffer_alloc() function.  It will trigger a WARN_ON() at the
start of fb_deferred_io_init() and the function will not do anything.

Fixes: 856082f021a2 ("fbdev: defio: fix the pagelist corruption")

Signed-off-by: Peter Suti <peter.suti@streamunlimited.com>
---
 drivers/staging/fbtft/fbtft-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index 9b3eaed80cdd..afaba94d1d1c 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -654,7 +654,6 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 	fbdefio->delay =            HZ / fps;
 	fbdefio->sort_pagereflist = true;
 	fbdefio->deferred_io =      fbtft_deferred_io;
-	fb_deferred_io_init(info);
 
 	snprintf(info->fix.id, sizeof(info->fix.id), "%s", dev->driver->name);
 	info->fix.type =           FB_TYPE_PACKED_PIXELS;
@@ -665,6 +664,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 	info->fix.line_length =    width * bpp / 8;
 	info->fix.accel =          FB_ACCEL_NONE;
 	info->fix.smem_len =       vmem_size;
+	fb_deferred_io_init(info);
 
 	info->var.rotate =         pdata->rotate;
 	info->var.xres =           width;
-- 
2.25.1