Patch "drm/i915/fbdev: lock the fbdev obj before vma pin" has been added to the 6.2-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/i915/fbdev: lock the fbdev obj before vma pin

to the 6.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-fbdev-lock-the-fbdev-obj-before-vma-pin.patch
and it can be found in the queue-6.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6d14ad2302ea2bdeab42035f308f501a1bf018df
Author: Tejas Upadhyay <tejas.upadhyay@xxxxxxxxx>
Date:   Wed Mar 1 12:10:52 2023 -0800

    drm/i915/fbdev: lock the fbdev obj before vma pin
    
    [ Upstream commit ed00eba03474adbf525ff03d69705d8c78b76456 ]
    
    lock the fbdev obj before calling into
    i915_vma_pin_iomap(). This helps to solve below :
    
    <7>[   93.563308] i915 0000:00:02.0: [drm:intelfb_create [i915]] no BIOS fb, allocating a new one
    <4>[   93.581844] ------------[ cut here ]------------
    <4>[   93.581855] WARNING: CPU: 12 PID: 625 at drivers/gpu/drm/i915/gem/i915_gem_pages.c:424 i915_gem_object_pin_map+0x152/0x1c0 [i915]
    
    Fixes: f0b6b01b3efe ("drm/i915: Add ww context to intel_dpt_pin, v2.")
    Cc: Chris Wilson <chris.p.wilson@xxxxxxxxx>
    Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
    Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
    Signed-off-by: Tejas Upadhyay <tejas.upadhyay@xxxxxxxxx>
    Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@xxxxxxxxx>
    Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20230301201053.928709-5-radhakrishna.sripada@xxxxxxxxx
    (cherry picked from commit 561b31acfd65502a2cda2067513240fc57ccdbdc)
    Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
index 17e8bf2ac0e51..3a708bd73a000 100644
--- a/drivers/gpu/drm/i915/display/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
@@ -210,6 +210,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
 	bool prealloc = false;
 	void __iomem *vaddr;
 	struct drm_i915_gem_object *obj;
+	struct i915_gem_ww_ctx ww;
 	int ret;
 
 	mutex_lock(&ifbdev->hpd_lock);
@@ -290,13 +291,24 @@ static int intelfb_create(struct drm_fb_helper *helper,
 		info->fix.smem_len = vma->size;
 	}
 
-	vaddr = i915_vma_pin_iomap(vma);
-	if (IS_ERR(vaddr)) {
-		drm_err(&dev_priv->drm,
-			"Failed to remap framebuffer into virtual memory (%pe)\n", vaddr);
-		ret = PTR_ERR(vaddr);
-		goto out_unpin;
+	for_i915_gem_ww(&ww, ret, false) {
+		ret = i915_gem_object_lock(vma->obj, &ww);
+
+		if (ret)
+			continue;
+
+		vaddr = i915_vma_pin_iomap(vma);
+		if (IS_ERR(vaddr)) {
+			drm_err(&dev_priv->drm,
+				"Failed to remap framebuffer into virtual memory (%pe)\n", vaddr);
+			ret = PTR_ERR(vaddr);
+			continue;
+		}
 	}
+
+	if (ret)
+		goto out_unpin;
+
 	info->screen_base = vaddr;
 	info->screen_size = vma->size;