releases/4.19.31/parport_pc-fix-find_superio-io-compare-code-should-use-equal-test.patch

   1 From 21698fd57984cd28207d841dbdaa026d6061bceb Mon Sep 17 00:00:00 2001
   2 From: QiaoChong <qiaochong@loongson.cn>
   3 Date: Sat, 9 Feb 2019 20:59:07 +0000
   4 Subject: parport_pc: fix find_superio io compare code, should use equal test.
   5
   6 From: QiaoChong <qiaochong@loongson.cn>
   7
   8 commit 21698fd57984cd28207d841dbdaa026d6061bceb upstream.
   9
  10 In the original code before 181bf1e815a2 the loop was continuing until
  11 it finds the first matching superios[i].io and p->base.
  12 But after 181bf1e815a2 the logic changed and the loop now returns the
  13 pointer to the first mismatched array element which is then used in
  14 get_superio_dma() and get_superio_irq() and thus returning the wrong
  15 value.
  16 Fix the condition so that it now returns the correct pointer.
  17
  18 Fixes: 181bf1e815a2 ("parport_pc: clean up the modified while loops using for")
  19 Cc: Alan Cox <alan@linux.intel.com>
  20 Cc: stable@vger.kernel.org
  21 Signed-off-by: QiaoChong <qiaochong@loongson.cn>
  22 [rewrite the commit message]
  23 Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25
  26 ---
  27  drivers/parport/parport_pc.c |    2 +-
  28  1 file changed, 1 insertion(+), 1 deletion(-)
  29
  30 --- a/drivers/parport/parport_pc.c
  31 +++ b/drivers/parport/parport_pc.c
  32 @@ -1377,7 +1377,7 @@ static struct superio_struct *find_super
  33  {
  34         int i;
  35         for (i = 0; i < NR_SUPERIOS; i++)
  36 -               if (superios[i].io != p->base)
  37 +               if (superios[i].io == p->base)
  38                         return &superios[i];
  39         return NULL;
  40  }