Re: kern/55198: When the video card is Intel Mobile965GMExpress,i915drmkmshaserror CPU pipe A FIFO underrun, also X freezes/hangs

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

The following reply was made to PR kern/55198; it has been noted by GNATS.

From: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: tsutsui%ceres.dti.ne.jp@localhost
Subject: Re: kern/55198: When the video card is Intel Mobile965GMExpress,i915drmkmshaserror
	  CPU pipe A FIFO underrun, also X freezes/hangs
Date: Sat, 27 Jun 2020 21:41:55 +0900

 There is a report (from isaki@) that SNA has some problem also
 on ThinkPad X201s (i7-L620), i.e. Gen5 Ironlake.
 I've also confirmed Gen7 (IvyBridge i7-3770) works.
 
 Here is an updated summary:
 
 https://github.com/NetBSD/xsrc/blob/trunk/external/mit/xf86-video-intel/dist/src/intel_module.c
 https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units
 
 ---
 Gen1
  810 OK (SNA is not used)
 
 Gen2
  830M  OK (tsutsui@, Panasonic CF-R1)
  845M  OK (jdbaker@)
  855GM OK (tsutsui@, CF-R3; xdm has problems, but it also happens on UXA)
  865G  ??
 
 Gen3
  915G (GMA 900)  OK (jdbaker@)
  945G (GMA 950)  NG (jdbaker@)
  G33  (GMA 3100) NG? (there is a blog that says SNA failed on FreeBSD 12.1)
  N455 (GMA 3150) NG (tsutsui@, MSI U135DX)
 
 Gen4
  Q965 (GMA 3000)    ??
  G965 (GMA X3000)   NG (joaopaulo1511@, Acer Aspire 5720Z in this PR)
  G41  (GMA X4500)   NG (jdbaker@)
  Q45  (GMA X4500HD) NG (jdbaker@)
 
 Gen5
  Ironlake NG (isaki@, ThinkPad X201s; xdm corruption, UXA works)
 
 Gen6
  SandyBridge ??
 
 Gen7
  IvyBridge OK (tsutsui@, DELL Optiplex 9010)
 
 ---
 
 I'll commit the attached version RSN and send a pullup request.
 ---
 Index: intel_module.c
 ===================================================================
 RCS file: /cvsroot/xsrc/external/mit/xf86-video-intel/dist/src/intel_module.c,v
 retrieving revision 1.1.1.4
 diff -u -p -d -r1.1.1.4 intel_module.c
 --- intel_module.c	20 Mar 2019 06:34:02 -0000	1.1.1.4
 +++ intel_module.c	27 Jun 2020 12:15:05 -0000
 @@ -567,9 +567,8 @@ _xf86findDriver(const char *ident, XF86C
  	return NULL;
  }
  
 -static enum accel_method { NOACCEL, SNA, UXA } get_accel_method(void)
 +static enum accel_method { NOACCEL, SNA, UXA } get_accel_method(enum accel_method accel_method)
  {
 -	enum accel_method accel_method = DEFAULT_ACCEL_METHOD;
  	XF86ConfDevicePtr dev;
  
  	if (hosted())
 @@ -641,7 +640,17 @@ intel_scrn_create(DriverPtr		driver,
  #endif
  
  #if KMS
 -	switch (get_accel_method()) {
 +	enum accel_method default_accel_method = DEFAULT_ACCEL_METHOD;
 +	/*
 +	 * XXX
 +	 * Use UXA by default for Gen3/4/5 chipsets (except 915) to avoid
 +	 * screen corruption etc.  (PR/54995, PR/55198)
 +	 */
 +	if ((unsigned)((struct intel_device_info *)match_data)->gen > 030 &&
 +	    (unsigned)((struct intel_device_info *)match_data)->gen < 060)
 +		default_accel_method = UXA;
 +
 +	switch (get_accel_method(default_accel_method)) {
  #if USE_SNA
  	case NOACCEL:
  	case SNA:
 
 ---
 
 Note I think the options "TearFree" should be checked independently.
 
 ---
 Izumi Tsutsui