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[ Upstream commit7aeb353802] Commit 6726fbff19bf ("pinctrl: aspeed: Fix GPI only function problem.") fixes access to GPIO banks T and U on the AST2600. Both banks contain input-only pins and the GPIO pin function is named GPITx and GPIUx respectively. Unfortunately the fix had a negative impact on GPIO banks D and E for the AST2400 and AST2500 where the GPIO pass-through functions take similar "GPI"-style names. The net effect on the older SoCs was that when the GPIO subsystem requested a pin in banks D or E be muxed for GPIO, they were instead muxed for pass-through mode. Mistakenly muxing pass-through mode e.g. breaks booting the host on IBM's Witherspoon (AC922) platform where GPIOE0 is used for FSI. Further exploit the names in the provided expression structure to differentiate pass-through from pin-specific GPIO modes. This follow-up fix gives the expected behaviour for the following tests: Witherspoon BMC (AST2500): 1. Power-on the Witherspoon host 2. Request GPIOD1 be muxed via /sys/class/gpio/export 3. Request GPIOE1 be muxed via /sys/class/gpio/export 4. Request the balls for GPIOs E2 and E3 be muxed as GPIO pass-through ("GPIE2" mode) via a pinctrl hog in the devicetree Rainier BMC (AST2600): 5. Request GPIT0 be muxed via /sys/class/gpio/export 6. Request GPIU0 be muxed via /sys/class/gpio/export Together the tests demonstrate that all three pieces of functionality (general GPIOs via 1, 2 and 3, input-only GPIOs via 5 and 6, pass-through mode via 4) operate as desired across old and new SoCs. Fixes:9b92f5c51e("pinctrl: aspeed: Fix GPI only function problem.") Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Tested-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Joel Stanley <joel@jms.id.au> Cc: Billy Tsai <billy_tsai@aspeedtech.com> Cc: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/20201126063337.489927-1-andrew@aj.id.au Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.