Merge tag 'arm-drivers-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

Pull ARM driver updates from Arnd Bergmann:
 "The drivers branch for 6.1 is a bit larger than for most releases.

  Most of the changes come from SoC maintainers for the drivers/soc
  subsystem:

   - A new driver for error handling on the NVIDIA Tegra 'control
     backbone' bus.

   - A new driver for Qualcomm LLCC/DDR bandwidth measurement

   - New Rockchip rv1126 and rk3588 power domain drivers

   - DT binding updates for memory controllers, older Rockchip SoCs,
     various Mediatek devices, Qualcomm SCM firmware

   - Minor updates to Hisilicon LPC bus, the Allwinner SRAM driver, the
     Apple rtkit firmware driver, Tegra firmware

   - Minor updates for SoC drivers (Samsung, Mediatek, Renesas, Tegra,
     Qualcomm, Broadcom, NXP, ...)

  There are also some separate subsystem with downstream maintainers
  that merge updates this way:

   - Various updates and new drivers in the memory controller subsystem
     for Mediatek and Broadcom SoCs

   - Small set of changes in preparation to add support for FF-A v1.1
     specification later, in the Arm FF-A firmware subsystem

   - debugfs support in the PSCI firmware subsystem"

* tag 'arm-drivers-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (149 commits)
  ARM: remove check for CONFIG_DEBUG_LL_SER3
  firmware/psci: Add debugfs support to ease debugging
  firmware/psci: Print a warning if PSCI doesn't accept PC mode
  dt-bindings: memory: snps,dw-umctl2-ddrc: Extend schema with IRQs/resets/clocks props
  dt-bindings: memory: snps,dw-umctl2-ddrc: Replace opencoded numbers with macros
  dt-bindings: memory: snps,dw-umctl2-ddrc: Use more descriptive device name
  dt-bindings: memory: synopsys,ddrc-ecc: Detach Zynq DDRC controller support
  soc: sunxi: sram: Add support for the D1 system control
  soc: sunxi: sram: Export the LDO control register
  soc: sunxi: sram: Save a pointer to the OF match data
  soc: sunxi: sram: Return void from the release function
  soc: apple: rtkit: Add apple_rtkit_poll
  soc: imx: add i.MX93 media blk ctrl driver
  soc: imx: add i.MX93 SRC power domain driver
  soc: imx: imx8m-blk-ctrl: Use genpd_xlate_onecell
  soc: imx: imx8mp-blk-ctrl: handle PCIe PHY resets
  soc: imx: imx8m-blk-ctrl: add i.MX8MP VPU blk ctrl
  soc: imx: add i.MX8MP HDMI blk ctrl HDCP/HRV_MWR
  soc: imx: add icc paths for i.MX8MP hsio/hdmi blk ctrl
  soc: imx: add icc paths for i.MX8MP media blk ctrl
  ...

1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/soc/bcm/brcmstb/pm/pm-arm.c b/drivers/soc/bcm/brcmstb/pm/pm-arm.c
index 775da69b8efa..d681cd24c6e1 100644
--- a/drivers/soc/bcm/brcmstb/pm/pm-arm.c
+++ b/drivers/soc/bcm/brcmstb/pm/pm-arm.c
@@ -25,7 +25,6 @@
 #include <linux/kernel.h>
 #include <linux/memblock.h>
 #include <linux/module.h>
-#include <linux/notifier.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/panic_notifier.h>
@@ -664,7 +663,20 @@ static void __iomem *brcmstb_ioremap_match(const struct of_device_id *matches,
 
 	return of_io_request_and_map(dn, index, dn->full_name);
 }
-
+/*
+ * The AON is a small domain in the SoC that can retain its state across
+ * various system wide sleep states and specific reset conditions; the
+ * AON DATA RAM is a small RAM of a few words (< 1KB) which can store
+ * persistent information across such events.
+ *
+ * The purpose of the below panic notifier is to help with notifying
+ * the bootloader that a panic occurred and so that it should try its
+ * best to preserve the DRAM contents holding that buffer for recovery
+ * by the kernel as opposed to wiping out DRAM clean again.
+ *
+ * Reference: comment from Florian Fainelli, at
+ * https://lore.kernel.org/lkml/781cafb0-8d06-8b56-907a-5175c2da196a@gmail.com
+ */
 static int brcmstb_pm_panic_notify(struct notifier_block *nb,
 		unsigned long action, void *data)
 {