f53d4c109a
gpmi_io clock needs to be gated off when changing the parent/dividers of enfc_clk_root (i.MX6Q/i.MX6UL) respectively qspi2_clk_root (i.MX6SX). Otherwise this rate change can lead to an unresponsive GPMI core which results in DMA timeouts and failed driver probe: [ 4.072318] gpmi-nand 112000.gpmi-nand: DMA timeout, last DMA ... [ 4.370355] gpmi-nand 112000.gpmi-nand: Chip: 0, Error -110 ... [ 4.375988] gpmi-nand 112000.gpmi-nand: Chip: 0, Error -22 [ 4.381524] gpmi-nand 112000.gpmi-nand: Error in ECC-based read: -22 [ 4.387988] gpmi-nand 112000.gpmi-nand: Chip: 0, Error -22 [ 4.393535] gpmi-nand 112000.gpmi-nand: Chip: 0, Error -22 ... Other than stated in i.MX 6 erratum ERR007117, it should be sufficient to gate only gpmi_io because all other bch/nand clocks are derived from different clock roots. The i.MX6 reference manuals state that changing clock muxers can cause glitches but are silent about changing dividers. But tests showed that these glitches can definitely happen on i.MX6ULL. For i.MX7D/8MM in turn, the manual guarantees that no glitches can happen when changing dividers. Co-developed-by: Stefan Riedmueller <s.riedmueller@phytec.de> Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de> Signed-off-by: Christian Eggers <ceggers@arri.de> Cc: stable@vger.kernel.org Acked-by: Han Xu <han.xu@nxp.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20211102202022.15551-2-ceggers@arri.de |
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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.