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4c2357f57d
In the commit 03de19212ea3 ("mmc: dw_mmc: introduce timer for broken
command transfer over scheme") we tried to calculate the expected
hardware command timeout value. Unfortunately that calculation isn't
quite correct in all cases. It used "bus_hz" but, as far as I can
tell, it's supposed to use the card clock. Let's account for the div
value, which is documented as 2x the value stored in the register, or
1 if the register is 0.
NOTE: It's not expected that this will actually fix anything important
since the 10 ms margin added by the function will pretty much dwarf
any calculations. The card clock should be 100 kHz at minimum and:
1000 ms/s * (255 * 2) / 100000 Hz.
Gives us 5.1 ms.
...so really the point of this patch is just to make the code more
"correct" in case anyone ever tries to remove the 10 ms buffer.
Fixes: 03de19212ea3 ("mmc: dw_mmc: introduce timer for broken command transfer over scheme")
Tested-by: Emil Renner Berthing <kernel@esmil.dk>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.