target/linux/bcm27xx/patches-5.15/950-0698-dtoverlay-Reduce-size-of-PCIE-IB-window-in-pcie-32-d.patch

   1 From e4402c2622756ab56d02159a8ff3c54165ab577c Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Thu, 3 Feb 2022 11:17:16 +0000
   4 Subject: [PATCH] dtoverlay: Reduce size of PCIE IB window in
   5  pcie-32-dma overlay
   6
   7 The PCIE inbound window is rounded up to a power of 2, so the default
   8 of 3GB rounds up to 4GB starting at 0. This prohibits the MSI vector
   9 sitting at 0x0_fffffffc, and causes warnings from some subsystems
  10 (eg ahci) of a 64bit address on a 32bit configuration.
  11
  12 Reduce the window down to 2GB to avoid this issue.
  13
  14 https://github.com/raspberrypi/linux/issues/4848
  15
  16 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  17 ---
  18  .../dts/overlays/pcie-32bit-dma-overlay.dts   | 20 +++++++++++++++++++
  19  1 file changed, 20 insertions(+)
  20
  21 --- a/arch/arm/boot/dts/overlays/pcie-32bit-dma-overlay.dts
  22 +++ b/arch/arm/boot/dts/overlays/pcie-32bit-dma-overlay.dts
  23 @@ -11,8 +11,28 @@
  24         fragment@0 {
  25                 target-path = "/aliases";
  26                 __overlay__ {
  27 +                       /*
  28 +                        * Removing this alias stops the firmware patching the
  29 +                        * PCIE DT dma-ranges based on the detected chip
  30 +                        * revision.
  31 +                        */
  32                         pcie0 = "";
  33                 };
  34         };
  35
  36 +       fragment@1 {
  37 +               target = <&pcie0>;
  38 +               __overlay__ {
  39 +                       /*
  40 +                        * The size of the range is rounded up to a power of 2,
  41 +                        * so the range ends up being 0-4GB, and the MSI vector
  42 +                        * gets pushed beyond 4GB.
  43 +                        */
  44 +                       #address-cells = <3>;
  45 +                       #size-cells = <2>;
  46 +                       dma-ranges = <0x02000000 0x0 0x00000000 0x0 0x00000000
  47 +                                     0x0 0x80000000>;
  48 +               };
  49 +       };
  50 +
  51  };