mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 12:28:41 +08:00
a338619bd7
When insmod zynqmp-dpsub.ko after rmmod it, system will hang with the error log as below: root@xilinx-zynqmp:~# insmod zynqmp-dpsub.ko [ 88.391289] [drm] Initialized zynqmp-dpsub 1.0.0 20130509 for fd4a0000.display on minor 0 [ 88.529906] Console: switching to colour frame buffer device 128x48 [ 88.549402] zynqmp-dpsub fd4a0000.display: [drm] fb0: zynqmp-dpsubdrm frame buffer device [ 88.571624] zynqmp-dpsub fd4a0000.display: ZynqMP DisplayPort Subsystem driver probed root@xilinx-zynqmp:~# rmmod zynqmp_dpsub [ 94.023404] Console: switching to colour dummy device 80x25 root@xilinx-zynqmp:~# insmod zynqmp-dpsub.ko <hang here> This is because that in zynqmp_dp_probe it tries to access some DP registers while the DP controller is still in the reset state. When running "rmmod zynqmp_dpsub", zynqmp_dp_reset(dp, true) in zynqmp_dp_phy_exit is called to force the DP controller into the reset state. Then insmod will call zynqmp_dp_probe to program the DP registers, but at this moment the DP controller hasn't been brought out of the reset state yet since the function zynqmp_dp_reset(dp, false) is called later and this will result the system hang. Releasing the reset to DP controller before any read/write operation to it will fix this issue. And for symmetry, move zynqmp_dp_reset() call from zynqmp_dp_phy_exit() to zynqmp_dp_remove(). Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| 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 | ||
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.