295a0d0b55
On BDW, when host physical screen and guest virtual screen aren't on the same DDI port, guest i915 driver prints the following error and stop running. [ 6.775873] BUG: unable to handle kernel NULL pointer dereference at 0000000000000068 [ 6.775928] IP: intel_ddi_clock_get+0x81/0x430 [i915] [ 6.776206] Call Trace: [ 6.776233] ? vgpu_read32+0x4f/0x100 [i915] [ 6.776264] intel_ddi_get_config+0x11c/0x230 [i915] [ 6.776298] intel_modeset_setup_hw_state+0x313/0xd40 [i915] [ 6.776334] intel_modeset_init+0xe49/0x18d0 [i915] [ 6.776368] ? vgpu_write32+0x53/0x100 [i915] [ 6.776731] ? intel_i2c_reset+0x42/0x50 [i915] [ 6.777085] ? intel_setup_gmbus+0x32a/0x350 [i915] [ 6.777427] i915_driver_load+0xabc/0x14d0 [i915] [ 6.777768] i915_pci_probe+0x4f/0x70 [i915] The null pointer is guest intel_crtc_state->shared_dpll which is setted in haswell_get_ddi_pll(). When guest and host screen are on different DDI port, host driver won't set PORT_CLK_SET(guest_port), so haswell_get_ddi_pll() will return null and don't set pipe_config->shared_dpll, once the following program refernce this structure, it will print the above error. This patch set the initial val of guest PORT_CLK_SEL(guest_port) to LCPLL_810. And guest i915 driver will reset this value according to guest screen mode. Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> |
||
|---|---|---|
| Documentation | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.