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From: linux@roeck-us.net (Guenter Roeck)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] hwmon: xgene: access mailbox as RAM
Date: Fri, 9 Sep 2016 14:56:53 -0700	[thread overview]
Message-ID: <20160909215653.GA2362@roeck-us.net> (raw)
In-Reply-To: <3475893.910N1IvcYZ@wuerfel>

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

  parent reply	other threads:[~2016-09-09 21:56 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-21 20:55 [PATCH v3 0/3] hwmon: xgene: Add support for X-Gene hwmon driver Hoan Tran
2016-07-21 20:55 ` [PATCH v3 1/3] Documentation: dtb: xgene: Add hwmon dts binding documentation Hoan Tran
2016-07-21 22:02   ` Guenter Roeck
2016-07-21 20:55 ` [PATCH v3 2/3] hwmon: xgene: Add hwmon driver Hoan Tran
2016-07-21 22:09   ` Guenter Roeck
2016-07-21 22:21     ` Hoan Tran
2016-08-01 13:21   ` kbuild test robot
2016-08-01 16:39     ` Hoan Tran
2016-09-07 21:41   ` Arnd Bergmann
2016-09-07 22:27     ` Guenter Roeck
2016-09-08  8:15       ` Arnd Bergmann
2016-09-08 14:55         ` Guenter Roeck
2016-09-08 14:59           ` Arnd Bergmann
2016-09-07 22:37     ` Guenter Roeck
2016-09-08  8:14       ` Arnd Bergmann
2016-09-08 10:47         ` James Morse
2016-09-09  3:18           ` AKASHI Takahiro
2016-09-09  9:31             ` James Morse
2016-09-09 15:38       ` Arnd Bergmann
2016-09-09 15:38       ` [PATCH] hwmon: xgene: access mailbox as RAM Arnd Bergmann
2016-09-09 16:58         ` Guenter Roeck
2016-09-09 17:05           ` Hoan Tran
2016-09-09 19:24         ` Hoan Tran
2016-09-09 19:58           ` Arnd Bergmann
2016-09-09 20:10             ` [PATCH v2] " Arnd Bergmann
2016-09-09 20:47               ` Hoan Tran
2016-09-09 21:56               ` Guenter Roeck [this message]
2016-09-09 20:43             ` [PATCH] " Hoan Tran
2016-09-09 20:50               ` Arnd Bergmann
2016-09-09 20:51                 ` Hoan Tran
2016-07-21 20:55 ` [PATCH v3 3/3] arm64: dts: apm: Add X-Gene SoC hwmon to device tree Hoan Tran
2016-07-21 22:09   ` Guenter Roeck

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