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From ed04fe8a0e87d7b5ea17d47f4ac9ec962b24814a Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon, 3 May 2021 13:57:33 +0200
Subject: Revert "video: imsttfb: fix potential NULL pointer dereferences"
Git-commit: ed04fe8a0e87d7b5ea17d47f4ac9ec962b24814a
Patch-mainline: v5.13-rc3
References: bsc#1129770

This reverts commit 1d84353d205a953e2381044953b7fa31c8c9702d.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

The original commit here, while technically correct, did not fully
handle all of the reported issues that the commit stated it was fixing,
so revert it until it can be "fixed" fully.

Note, ioremap() probably will never fail for old hardware like this, and
if anyone actually used this hardware (a PowerMac era PCI display card),
they would not be using fbdev anymore.

Cc: Kangjie Lu <kjlu@umn.edu>
Cc: Aditya Pakki <pakki001@umn.edu>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Fixes: 1d84353d205a ("video: imsttfb: fix potential NULL pointer dereferences")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-67-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/fbdev/imsttfb.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c
index 3ac053b88495..e04411701ec8 100644
--- a/drivers/video/fbdev/imsttfb.c
+++ b/drivers/video/fbdev/imsttfb.c
@@ -1512,11 +1512,6 @@ static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	info->fix.smem_start = addr;
 	info->screen_base = (__u8 *)ioremap(addr, par->ramdac == IBM ?
 					    0x400000 : 0x800000);
-	if (!info->screen_base) {
-		release_mem_region(addr, size);
-		framebuffer_release(info);
-		return -ENOMEM;
-	}
 	info->fix.mmio_start = addr + 0x800000;
 	par->dc_regs = ioremap(addr + 0x800000, 0x1000);
 	par->cmap_regs_phys = addr + 0x840000;
-- 
2.37.3