c8ab5ac30c
Guest kernel will write to BXT_PHY_CTL_FAMILY to reset DDI PHY
and pull BXT_PHY_CTL to check PHY status. Previous handling will
set/reset BXT_PHY_CTL of all PHYs at same time on receiving vreg
write to some BXT_PHY_CTL_FAMILY. If some BXT_PHY_CTL is already
enabled, following reset to another BXT_PHY_CTL_FAMILY will clear
the enabled BXT_PHY_CTL, which result in guest kernel print:
-----------------------------------
[drm:intel_ddi_get_hw_state [i915]]
*ERROR* Port B enabled but PHY powered down? (PHY_CTL 00000000)
-----------------------------------
The correct handling should operate BXT_PHY_CTL_FAMILY and
BXT_PHY_CTL on the same DDI.
v2: Use correct reg define. The naming looks confusing, however
current i915_reg.h bind DPIO_PHY0 to _PHY_CTL_FAMILY_DDI and
bind DPIO_PHY1 to _PHY_CTL_FAMILY_EDP, pairing to
_BXT_PHY_CTL_DDI_A and _BXT_PHY_CTL_DDI_B respectively.
v3: v2 incorrectly map _PHY_CTL_FAMILY_EDP to _BXT_PHY_CTL_DDI_A.
BXT_PHY_CTL() looks up DDI using PORTx but not PHYx. Based on
DPIO_PHY to DDI mapping, make correct vreg handle to BXT_PHY_CTL
on receiving vreg write to BXT_PHY_CTL_FAMILY. (He, Min)
Current mapping according to bxt_power_wells:
dpio-common-a:
>>> DPIO_PHY1
>>> BXT_DPIO_CMN_A_POWER_DOMAINS
>>> POWER_DOMAIN_PORT_DDI_A_LANES
>>> PORT_A
dpio-common-bc:
>>> DPIO_PHY0
>>> BXT_DPIO_CMN_BC_POWER_DOMAINS
>>> POWER_DOMAIN_PORT_DDI_B_LANES | POWER_DOMAIN_PORT_DDI_C_LANES
>>> PORT_B or PORT_C
Signed-off-by: Colin Xu <colin.xu@intel.com>
Reviewed-by: He, Min <min.he@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.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.
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.