target/linux/generic/backport-5.15/409-v6.3-mtd-mtdpart-Don-t-create-platform-device-that-ll-nev.patch

   1 From fb42378dcc7f247df56f0ecddfdae85487495fbc Mon Sep 17 00:00:00 2001
   2 From: Saravana Kannan <saravanak@google.com>
   3 Date: Mon, 6 Feb 2023 17:42:04 -0800
   4 Subject: [PATCH] mtd: mtdpart: Don't create platform device that'll never
   5  probe
   6
   7 These "nvmem-cells" platform devices never get probed because there's no
   8 platform driver for it and it's never used anywhere else. So it's a
   9 waste of memory. These devices also cause fw_devlink to block nvmem
  10 consumers of "nvmem-cells" partition from probing because the supplier
  11 device never probes.
  12
  13 So stop creating platform devices for nvmem-cells partitions to avoid
  14 wasting memory and to avoid blocking probing of consumers.
  15
  16 Reported-by: Maxim Kiselev <bigunclemax@gmail.com>
  17 Fixes: bcdf0315a61a ("mtd: call of_platform_populate() for MTD partitions")
  18 Signed-off-by: Saravana Kannan <saravanak@google.com>
  19 Tested-by: Maksim Kiselev <bigunclemax@gmail.com>
  20 Tested-by: Douglas Anderson <dianders@chromium.org>
  21 Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
  22 Tested-by: Luca Weiss <luca.weiss@fairphone.com> # qcom/sm7225-fairphone-fp4
  23 Link: https://lore.kernel.org/r/20230207014207.1678715-13-saravanak@google.com
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25 ---
  26  drivers/mtd/mtdpart.c | 10 ++++++++++
  27  1 file changed, 10 insertions(+)
  28
  29 --- a/drivers/mtd/mtdpart.c
  30 +++ b/drivers/mtd/mtdpart.c
  31 @@ -577,6 +577,7 @@ static int mtd_part_of_parse(struct mtd_
  32  {
  33         struct mtd_part_parser *parser;
  34         struct device_node *np;
  35 +       struct device_node *child;
  36         struct property *prop;
  37         struct device *dev;
  38         const char *compat;
  39 @@ -594,6 +595,15 @@ static int mtd_part_of_parse(struct mtd_
  40         else
  41                 np = of_get_child_by_name(np, "partitions");
  42
  43 +       /*
  44 +        * Don't create devices that are added to a bus but will never get
  45 +        * probed. That'll cause fw_devlink to block probing of consumers of
  46 +        * this partition until the partition device is probed.
  47 +        */
  48 +       for_each_child_of_node(np, child)
  49 +               if (of_device_is_compatible(child, "nvmem-cells"))
  50 +                       of_node_set_flag(child, OF_POPULATED);
  51 +
  52         of_property_for_each_string(np, "compatible", prop, compat) {
  53                 parser = mtd_part_get_compatible_parser(compat);
  54                 if (!parser)