RFC: libdrm: Support Iris Graphics 540 & 550 (Skylake GT3e)

[Thorsten Leemhuis]

Lo! Below patch adds the PCI-ID for the Intel(R) Iris Graphics 550 (Skylake
GT3e mobile) to libdrm. It afaics is the last piece that is missing to
make those GPUs work properly, as Linux 4.6-rc(¹) and Mesa 11.2 already
support it – but without this patch I get a "error initializing buffer
manager" message from i965 when it tries to load. I tested it on a
laptop with a Core i5-6267U and it seems to work -- but I only did a
few quick tests so far.

Could someone @Intel please comment if this patch should be enough to
make libdrm support this GPU properly? And while at it could you please
tell me proper code identifiers for the Iris Graphics 540 and 550? Then I 
can update the patch to use a better name (I assume the "SKYLAKE_GT3E" I   
used in my patch is misleading) and add support for the 540 (0x1923) as 
well.

tia, cu, knurd

(¹)
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7157bb27e79875db5603aa1e30f56e873a8300f9


diff -Naur libdrm-2.4.67.org/intel/intel_chipset.h libdrm-2.4.67/intel/intel_chipset.h
--- libdrm-2.4.67.org/intel/intel_chipset.h	2016-01-17 22:22:14.000000000 +0100
+++ libdrm-2.4.67/intel/intel_chipset.h	2016-04-26 10:53:02.937389821 +0200
@@ -180,6 +180,7 @@
 #define PCI_CHIP_SKYLAKE_ULX_GT2	0x191E
 #define PCI_CHIP_SKYLAKE_MOBILE_GT2	0x1921 /* Reserved */
 #define PCI_CHIP_SKYLAKE_GT3		0x1926
+#define PCI_CHIP_SKYLAKE_GT3E		0x1927
 #define PCI_CHIP_SKYLAKE_HALO_GT3	0x192B /* Reserved */
 #define PCI_CHIP_SKYLAKE_SRV_GT4	0x192A
 #define PCI_CHIP_SKYLAKE_DT_GT4		0x1932
@@ -390,6 +391,7 @@
 				 (devid) == PCI_CHIP_SKYLAKE_MOBILE_GT2)
 
 #define IS_SKL_GT3(devid)	((devid) == PCI_CHIP_SKYLAKE_GT3	|| \
+				 (devid) == PCI_CHIP_SKYLAKE_GT3E	|| \
 				 (devid) == PCI_CHIP_SKYLAKE_HALO_GT3)
 
 #define IS_SKL_GT4(devid)	((devid) == PCI_CHIP_SKYLAKE_SRV_GT4	|| \