2a1c7cda52
Through mmc_poll_for_busy() a CMD13 may be sent to get the status of the (e)MMC card. If the state of the card is R1_STATE_PRG, the card is considered as being busy, which means we continue to poll with CMD13. This seems to be sufficient, but it's also unnecessary fragile, as it means a new command/request could potentially be sent to the card when it's in an unknown state. To try to improve the situation, but also to move towards a more consistent CMD13 polling behaviour in the mmc core, let's deploy the same policy we use for regular I/O write requests. In other words, let's check that card returns to the R1_STATE_TRAN and that the R1_READY_FOR_DATA bit is set in the CMD13 response, before exiting the polling loop. Note that, potentially this changed behaviour could lead to unnecessary waiting for the timeout to expire, if the card for some reason, moves to an unexpected error state. However, as we bail out from the polling loop when R1_SWITCH_ERROR bit is set or when the CMD13 fails, this shouldn't be an issue. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Baolin Wang <baolin.wang7@gmail.com> Tested-by: Ludovic Barre <ludovic.barre@st.com> Reviewed-by: Ludovic Barre <ludovic.barre@st.com> Link: https://lore.kernel.org/r/20200204085449.32585-8-ulf.hansson@linaro.org |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.