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Re: [PATCH v2] hwmon: xgene: access mailbox as RAM

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On Fri, Sep 09, 2016 at 10:10:45PM +0200, Arnd Bergmann wrote:
> The newly added hwmon driver fails to build in an allmodconfig
> kernel:
> 
>       ERROR: "memblock_is_memory" [drivers/hwmon/xgene-hwmon.ko] undefined!
> 
> According to comments in the code, the mailbox is a shared memory region,
> not a set of MMIO registers, so we should use memremap() for mapping it
> instead of ioremap or acpi_os_ioremap, and pointer dereferences instead
> of readl/writel.
> 
> The driver already uses plain kernel pointers, so it's a bit unusual
> to work with functions that operate on __iomem pointers, and this
> fixes that part too.
> 
> I'm using READ_ONCE/WRITE_ONCE here to keep the existing behavior
> regarding the ordering of the accesses from the CPU, but note that
> there are no barriers (also unchanged from before).
> 
> I'm also keeping the endianess behavior, though I'm unsure whether
> the message data was supposed to be in LE32 format in the first
> place, it's possible this was meant to be interpreted as a byte
> stream instead.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied after 's/endianess/endianness/' to make checkpatch happy.

Thanks,
Guenter

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Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Arnd Bergmann <arnd@arndb.de> - 2016-09-07 23:50 +0200
  Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Guenter Roeck <linux@roeck-us.net> - 2016-09-08 00:30 +0200
    Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Arnd Bergmann <arnd@arndb.de> - 2016-09-08 10:20 +0200
      Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Guenter Roeck <linux@roeck-us.net> - 2016-09-08 17:00 +0200
        Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Arnd Bergmann <arnd@arndb.de> - 2016-09-08 17:10 +0200
  Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Guenter Roeck <linux@roeck-us.net> - 2016-09-08 00:40 +0200
    Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Arnd Bergmann <arnd@arndb.de> - 2016-09-08 10:20 +0200
      Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver James Morse <james.morse@arm.com> - 2016-09-08 12:50 +0200
        Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver AKASHI Takahiro <takahiro.akashi@linaro.org> - 2016-09-09 05:20 +0200
          Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver James Morse <james.morse@arm.com> - 2016-09-09 11:40 +0200
    Re: [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Arnd Bergmann <arnd@arndb.de> - 2016-09-09 17:50 +0200
    [PATCH] hwmon: xgene: access mailbox as RAM Arnd Bergmann <arnd@arndb.de> - 2016-09-09 17:50 +0200
      Re: [PATCH] hwmon: xgene: access mailbox as RAM Guenter Roeck <linux@roeck-us.net> - 2016-09-09 19:00 +0200
        Re: [PATCH] hwmon: xgene: access mailbox as RAM Hoan Tran <hotran@apm.com> - 2016-09-09 19:10 +0200
      Re: [PATCH] hwmon: xgene: access mailbox as RAM Hoan Tran <hotran@apm.com> - 2016-09-09 21:30 +0200
        Re: [PATCH] hwmon: xgene: access mailbox as RAM Arnd Bergmann <arnd@arndb.de> - 2016-09-09 22:10 +0200
          [PATCH v2] hwmon: xgene: access mailbox as RAM Arnd Bergmann <arnd@arndb.de> - 2016-09-09 22:20 +0200
            Re: [PATCH v2] hwmon: xgene: access mailbox as RAM Hoan Tran <hotran@apm.com> - 2016-09-09 22:50 +0200
            Re: [PATCH v2] hwmon: xgene: access mailbox as RAM Guenter Roeck <linux@roeck-us.net> - 2016-09-10 00:00 +0200
          Re: [PATCH] hwmon: xgene: access mailbox as RAM Hoan Tran <hotran@apm.com> - 2016-09-09 22:50 +0200
            Re: [PATCH] hwmon: xgene: access mailbox as RAM Arnd Bergmann <arnd@arndb.de> - 2016-09-09 23:00 +0200
              Re: [PATCH] hwmon: xgene: access mailbox as RAM Hoan Tran <hotran@apm.com> - 2016-09-09 23:00 +0200

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