a19effb6db
The Runtime PM subsystem will force the device "fd4a0000.zynqmp-display" to enter suspend state while booting if the following conditions are met: - the usage counter is zero (pm_runtime_get_sync hasn't been called yet) - no 'active' children (no zynqmp-dp-snd-xx node under dpsub node) - no other device in the same power domain (dpdma node has no "power-domains = <&zynqmp_firmware PD_DP>" property) So there is a scenario as below: 1) DP device enters suspend state <- call zynqmp_gpd_power_off 2) zynqmp_disp_crtc_setup_clock <- configurate register VPLL_FRAC_CFG 3) pm_runtime_get_sync <- call zynqmp_gpd_power_on and clear previous VPLL_FRAC_CFG configuration 4) clk_prepare_enable(disp->pclk) <- enable failed since VPLL_FRAC_CFG configuration is corrupted From above, we can see that pm_runtime_get_sync may clear register VPLL_FRAC_CFG configuration and result the failure of clk enabling. Putting pm_runtime_get_sync at the very beginning of the function zynqmp_disp_crtc_atomic_enable can resolve this issue. 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>
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.