[Intel-gfx] [PATCH v2 0/2] Report MMIO communication problems more clearly

[Intel-gfx] [PATCH v2 0/2] Report MMIO communication problems more clearly

[Andi Shyti]

Hi,

just copy pasting Matt's original cover letter:

We're periodically facing problems in CI where all registers read back
as 0xFFFFFFFF.  In general this is what happens when the CPU is unable
to communicate with a PCI device, so the transaction autocompletes with
all F's as a placeholder.  Sometimes the device will recover on its own,
sometimes it will never come back.

We already have some attempts to detect when this happens (e.g., when
checking FPGA_DBG), but let's add a couple more checks with descriptive
error messages to identify the problem in other cases:

 - When the device is first probed, we'll do an initial check of the GT
   forcewake register.  As a masked register, the upper bits should
   always come back as 0's if device access is behaving properly, so if
   we see all F's, we can conclude that the device is already in a bad
   state.  We'll wait two seconds to see if it recovers on its own, then
   give up on the device.

 - When we encounter a 'forcewake timed out while waiting for clear'
   error, we'll do one more read of the register to see if it's because
   we're just reading back all F's.  If so, we'll print a more
   meaningful message clarifying that it isn't the forcewake itself
   that's the problem, but rather communication with the device.

Note that this only captures the failure case where accessing the device
is problematic (resulting in registers giving all F's).  There's a
separate class of problems where the device is okay, but the GT inside
the device is busted and all GT registers read back as 0's (other
registers like sgunit registers are usually still readable).  This
series does not address that class of errors.

This is just a quick change to get some better CI error messages.  Some
ideas for future enhancements:

 - Try something to reset the device if we detect a problem at driver
   load (e.g., PCI FLR, toggling the PCI power state, etc.)?

 - Use something more standard like pci_read_config_dword() instead of a
   device register read to determine when we're not communicating
   properly?  Generally the PCI config space is also giving all F's at
   this point.

 - Also handle the "device OK, GT dead" case by finding some GT
   register(s) that should never be 0 on a functioning system.  Maybe
   one of the fuse registers would work for this?

Changelog
=========
v1 -> v2
 - The sanity check can use intel_wait_for_register_fw().
   (Thanks, Jani)

Matt Roper (2):
  drm/i915: Sanitycheck MMIO access early in driver load
  drm/i915: Check for unreliable MMIO during forcewake

 drivers/gpu/drm/i915/intel_uncore.c | 47 +++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 3 deletions(-)

-- 
2.39.2

[Intel-gfx] [PATCH v2 1/2] drm/i915: Sanitycheck MMIO access early in driver load

[Andi Shyti]

From: Matt Roper <matthew.d.roper@intel.com>

We occasionally see the PCI device in a non-accessible state at the
point the driver is loaded.  When this happens, all BAR accesses will
read back as 0xFFFFFFFF.  Rather than reading registers and
misinterpreting their (invalid) values, let's specifically check for
0xFFFFFFFF in a register that cannot have that value to see if the
device is accessible.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 35 +++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index e1e1f34490c8e..0b69081d6d285 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -2602,11 +2602,46 @@ static int uncore_forcewake_init(struct intel_uncore *uncore)
 	return 0;
 }
 
+static int sanity_check_mmio_access(struct intel_uncore *uncore)
+{
+	struct drm_i915_private *i915 = uncore->i915;
+	int ret;
+
+	if (GRAPHICS_VER(i915) < 8)
+		return 0;
+
+	/*
+	 * Sanitycheck that MMIO access to the device is working properly.  If
+	 * the CPU is unable to communcate with a PCI device, BAR reads will
+	 * return 0xFFFFFFFF.  Let's make sure the device isn't in this state
+	 * before we start trying to access registers.
+	 *
+	 * We use the primary GT's forcewake register as our guinea pig since
+	 * it's been around since HSW and it's a masked register so the upper
+	 * 16 bits can never read back as 1's if device access is operating
+	 * properly.
+	 *
+	 * If MMIO isn't working, we'll wait up to 2 seconds to see if it
+	 * recovers, then give up.
+	 */
+	ret = intel_wait_for_register_fw(uncore, FORCEWAKE_MT, 0, 0, 2000000);
+	if (ret == -ETIMEDOUT) {
+		drm_err(&i915->drm, "Device is non-operational; MMIO access returns 0xFFFFFFFF!\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
 int intel_uncore_init_mmio(struct intel_uncore *uncore)
 {
 	struct drm_i915_private *i915 = uncore->i915;
 	int ret;
 
+	ret = sanity_check_mmio_access(uncore);
+	if (ret)
+		return ret;
+
 	/*
 	 * The boot firmware initializes local memory and assesses its health.
 	 * If memory training fails, the punit will have been instructed to
-- 
2.39.2

[Intel-gfx] [PATCH v2 2/2] drm/i915: Check for unreliable MMIO during forcewake

[Andi Shyti]

From: Matt Roper <matthew.d.roper@intel.com>

Although we now sanitycheck MMIO access during driver load to make sure
the MMIO BAR isn't returning all 0xFFFFFFFF, there have been a few cases
where (temporarily?) unreliable MMIO access has happened after GPU
resets or power events.  We'll often notice this on our next GT register
access since forcewake handling will fail; let's change our handling
slightly so that when this happens we print a more meaningful message
clarifying that the problem is the MMIO access, not forcewake
specifically.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 0b69081d6d285..303a5d38c93a5 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -178,9 +178,15 @@ static inline void
 fw_domain_wait_ack_clear(const struct intel_uncore_forcewake_domain *d)
 {
 	if (wait_ack_clear(d, FORCEWAKE_KERNEL)) {
-		drm_err(&d->uncore->i915->drm,
-			"%s: timed out waiting for forcewake ack to clear.\n",
-			intel_uncore_forcewake_domain_to_str(d->id));
+		if (fw_ack(d) == ~0)
+			drm_err(&d->uncore->i915->drm,
+				"%s: MMIO unreliable (forcewake register returns 0xFFFFFFFF)!\n",
+				intel_uncore_forcewake_domain_to_str(d->id));
+		else
+			drm_err(&d->uncore->i915->drm,
+				"%s: timed out waiting for forcewake ack to clear.\n",
+				intel_uncore_forcewake_domain_to_str(d->id));
+
 		add_taint_for_CI(d->uncore->i915, TAINT_WARN); /* CI now unreliable */
 	}
 }
-- 
2.39.2

Re: [Intel-gfx] [PATCH v2 1/2] drm/i915: Sanitycheck MMIO access early in driver load

[Andi Shyti]

> We occasionally see the PCI device in a non-accessible state at the
> point the driver is loaded.  When this happens, all BAR accesses will
> read back as 0xFFFFFFFF.  Rather than reading registers and
> misinterpreting their (invalid) values, let's specifically check for
> 0xFFFFFFFF in a register that cannot have that value to see if the
> device is accessible.
> 
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>

Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>

Andi

Re: [Intel-gfx] [PATCH v2 2/2] drm/i915: Check for unreliable MMIO during forcewake

[Andi Shyti]

> Although we now sanitycheck MMIO access during driver load to make sure
> the MMIO BAR isn't returning all 0xFFFFFFFF, there have been a few cases
> where (temporarily?) unreliable MMIO access has happened after GPU
> resets or power events.  We'll often notice this on our next GT register
> access since forcewake handling will fail; let's change our handling
> slightly so that when this happens we print a more meaningful message
> clarifying that the problem is the MMIO access, not forcewake
> specifically.
> 
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>

Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>

Andi

[Intel-gfx] ✗ Fi.CI.BUILD: warning for Report MMIO communication problems more clearly (rev2)

[Patchwork]

== Series Details ==

Series: Report MMIO communication problems more clearly (rev2)
URL   : https://patchwork.freedesktop.org/series/115421/
State : warning

== Summary ==

Error: git fetch origin failed

[Intel-gfx] ✗ Fi.CI.DOCS: warning for Report MMIO communication problems more clearly (rev2)

[Patchwork]

== Series Details ==

Series: Report MMIO communication problems more clearly (rev2)
URL   : https://patchwork.freedesktop.org/series/115421/
State : warning

== Summary ==

Error: git fetch origin failed

[Intel-gfx] ✓ Fi.CI.BAT: success for Report MMIO communication problems more clearly (rev2)

[Patchwork]

[-- Attachment #1: Type: text/plain, Size: 7182 bytes --]

== Series Details ==

Series: Report MMIO communication problems more clearly (rev2)
URL   : https://patchwork.freedesktop.org/series/115421/
State : success

== Summary ==

CI Bug Log - changes from CI_DRM_12890 -> Patchwork_115421v2
====================================================

Summary
-------

  **SUCCESS**

  No regressions found.

  External URL: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/index.html

Participating hosts (36 -> 36)
------------------------------

  Additional (1): bat-atsm-1 
  Missing    (1): fi-snb-2520m 

Known issues
------------

  Here are the changes found in Patchwork_115421v2 that come from known issues:

### IGT changes ###

#### Issues hit ####

  * igt@fbdev@eof:
    - bat-atsm-1:         NOTRUN -> [SKIP][1] ([i915#2582]) +4 similar issues
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@fbdev@eof.html

  * igt@gem_mmap@basic:
    - bat-atsm-1:         NOTRUN -> [SKIP][2] ([i915#4083])
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@gem_mmap@basic.html

  * igt@gem_tiled_fence_blits@basic:
    - bat-atsm-1:         NOTRUN -> [SKIP][3] ([i915#4077]) +2 similar issues
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@gem_tiled_fence_blits@basic.html

  * igt@gem_tiled_pread_basic:
    - bat-atsm-1:         NOTRUN -> [SKIP][4] ([i915#4079]) +1 similar issue
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@gem_tiled_pread_basic.html

  * igt@i915_selftest@live@mman:
    - bat-rpls-2:         [PASS][5] -> [TIMEOUT][6] ([i915#6794])
   [5]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/bat-rpls-2/igt@i915_selftest@live@mman.html
   [6]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-rpls-2/igt@i915_selftest@live@mman.html

  * igt@i915_selftest@live@slpc:
    - bat-rpls-1:         [PASS][7] -> [DMESG-FAIL][8] ([i915#6367] / [i915#7996])
   [7]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/bat-rpls-1/igt@i915_selftest@live@slpc.html
   [8]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-rpls-1/igt@i915_selftest@live@slpc.html

  * igt@i915_suspend@basic-s3-without-i915:
    - bat-atsm-1:         NOTRUN -> [SKIP][9] ([i915#6645])
   [9]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@i915_suspend@basic-s3-without-i915.html

  * igt@kms_addfb_basic@size-max:
    - bat-atsm-1:         NOTRUN -> [SKIP][10] ([i915#6077]) +36 similar issues
   [10]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@kms_addfb_basic@size-max.html

  * igt@kms_cursor_legacy@basic-flip-after-cursor-atomic:
    - bat-atsm-1:         NOTRUN -> [SKIP][11] ([i915#6078]) +19 similar issues
   [11]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@kms_cursor_legacy@basic-flip-after-cursor-atomic.html

  * igt@kms_flip@basic-plain-flip:
    - bat-atsm-1:         NOTRUN -> [SKIP][12] ([i915#6166]) +3 similar issues
   [12]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@kms_flip@basic-plain-flip.html

  * igt@kms_force_connector_basic@prune-stale-modes:
    - bat-atsm-1:         NOTRUN -> [SKIP][13] ([i915#6093]) +3 similar issues
   [13]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@kms_force_connector_basic@prune-stale-modes.html

  * igt@kms_pipe_crc_basic@hang-read-crc:
    - bat-atsm-1:         NOTRUN -> [SKIP][14] ([i915#1836]) +6 similar issues
   [14]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@kms_pipe_crc_basic@hang-read-crc.html

  * igt@kms_pipe_crc_basic@read-crc:
    - bat-adlp-9:         NOTRUN -> [SKIP][15] ([i915#3546]) +1 similar issue
   [15]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-adlp-9/igt@kms_pipe_crc_basic@read-crc.html

  * igt@kms_prop_blob@basic:
    - bat-atsm-1:         NOTRUN -> [SKIP][16] ([i915#7357])
   [16]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@kms_prop_blob@basic.html

  * igt@kms_psr@sprite_plane_onoff:
    - bat-atsm-1:         NOTRUN -> [SKIP][17] ([i915#1072]) +3 similar issues
   [17]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@kms_psr@sprite_plane_onoff.html

  * igt@kms_setmode@basic-clone-single-crtc:
    - bat-atsm-1:         NOTRUN -> [SKIP][18] ([i915#6094])
   [18]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@kms_setmode@basic-clone-single-crtc.html

  * igt@prime_vgem@basic-fence-flip:
    - bat-atsm-1:         NOTRUN -> [SKIP][19] ([fdo#109295] / [i915#6078])
   [19]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@prime_vgem@basic-fence-flip.html

  * igt@prime_vgem@basic-fence-mmap:
    - bat-atsm-1:         NOTRUN -> [SKIP][20] ([fdo#109295] / [i915#4077]) +1 similar issue
   [20]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@prime_vgem@basic-fence-mmap.html

  * igt@prime_vgem@basic-write:
    - bat-atsm-1:         NOTRUN -> [SKIP][21] ([fdo#109295]) +3 similar issues
   [21]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/bat-atsm-1/igt@prime_vgem@basic-write.html

  
  [fdo#109295]: https://bugs.freedesktop.org/show_bug.cgi?id=109295
  [i915#1072]: https://gitlab.freedesktop.org/drm/intel/issues/1072
  [i915#1836]: https://gitlab.freedesktop.org/drm/intel/issues/1836
  [i915#2582]: https://gitlab.freedesktop.org/drm/intel/issues/2582
  [i915#3546]: https://gitlab.freedesktop.org/drm/intel/issues/3546
  [i915#4077]: https://gitlab.freedesktop.org/drm/intel/issues/4077
  [i915#4079]: https://gitlab.freedesktop.org/drm/intel/issues/4079
  [i915#4083]: https://gitlab.freedesktop.org/drm/intel/issues/4083
  [i915#6077]: https://gitlab.freedesktop.org/drm/intel/issues/6077
  [i915#6078]: https://gitlab.freedesktop.org/drm/intel/issues/6078
  [i915#6093]: https://gitlab.freedesktop.org/drm/intel/issues/6093
  [i915#6094]: https://gitlab.freedesktop.org/drm/intel/issues/6094
  [i915#6166]: https://gitlab.freedesktop.org/drm/intel/issues/6166
  [i915#6367]: https://gitlab.freedesktop.org/drm/intel/issues/6367
  [i915#6645]: https://gitlab.freedesktop.org/drm/intel/issues/6645
  [i915#6794]: https://gitlab.freedesktop.org/drm/intel/issues/6794
  [i915#7357]: https://gitlab.freedesktop.org/drm/intel/issues/7357
  [i915#7996]: https://gitlab.freedesktop.org/drm/intel/issues/7996


Build changes
-------------

  * Linux: CI_DRM_12890 -> Patchwork_115421v2

  CI-20190529: 20190529
  CI_DRM_12890: d4834b54c9207f50e07560f1be732a626a1f4bca @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_7210: 5f7116708590b55864456acd993ecdb02374a06f @ https://gitlab.freedesktop.org/drm/igt-gpu-tools.git
  Patchwork_115421v2: d4834b54c9207f50e07560f1be732a626a1f4bca @ git://anongit.freedesktop.org/gfx-ci/linux


### Linux commits

027a3ff3862a drm/i915: Check for unreliable MMIO during forcewake
c5a13075b5bf drm/i915: Sanitycheck MMIO access early in driver load

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/index.html

[-- Attachment #2: Type: text/html, Size: 8539 bytes --]

Re: [Intel-gfx] [PATCH v2 1/2] drm/i915: Sanitycheck MMIO access early in driver load

[Matt Roper]

On Tue, Mar 21, 2023 at 06:09:35PM +0100, Andi Shyti wrote:
> From: Matt Roper <matthew.d.roper@intel.com>
> 
> We occasionally see the PCI device in a non-accessible state at the
> point the driver is loaded.  When this happens, all BAR accesses will
> read back as 0xFFFFFFFF.  Rather than reading registers and
> misinterpreting their (invalid) values, let's specifically check for
> 0xFFFFFFFF in a register that cannot have that value to see if the
> device is accessible.
> 
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_uncore.c | 35 +++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index e1e1f34490c8e..0b69081d6d285 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -2602,11 +2602,46 @@ static int uncore_forcewake_init(struct intel_uncore *uncore)
>  	return 0;
>  }
>  
> +static int sanity_check_mmio_access(struct intel_uncore *uncore)
> +{
> +	struct drm_i915_private *i915 = uncore->i915;
> +	int ret;
> +
> +	if (GRAPHICS_VER(i915) < 8)
> +		return 0;
> +
> +	/*
> +	 * Sanitycheck that MMIO access to the device is working properly.  If
> +	 * the CPU is unable to communcate with a PCI device, BAR reads will
> +	 * return 0xFFFFFFFF.  Let's make sure the device isn't in this state
> +	 * before we start trying to access registers.
> +	 *
> +	 * We use the primary GT's forcewake register as our guinea pig since
> +	 * it's been around since HSW and it's a masked register so the upper
> +	 * 16 bits can never read back as 1's if device access is operating
> +	 * properly.
> +	 *
> +	 * If MMIO isn't working, we'll wait up to 2 seconds to see if it
> +	 * recovers, then give up.
> +	 */
> +	ret = intel_wait_for_register_fw(uncore, FORCEWAKE_MT, 0, 0, 2000000);

It looks like you lost the check for 0xFFFFFFFF specifically.  In fact
with a mask/value of 0, isn't this always going to just always pass
immediately?

We don't know what the value of this register will be (there may or may
not be some bits set), but we need to make sure that it isn't 0xFFFFFFFF
because that means we're not even truly accessing the register, just
hitting a PCI BAR read failure.


Matt

> +	if (ret == -ETIMEDOUT) {
> +		drm_err(&i915->drm, "Device is non-operational; MMIO access returns 0xFFFFFFFF!\n");
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
>  int intel_uncore_init_mmio(struct intel_uncore *uncore)
>  {
>  	struct drm_i915_private *i915 = uncore->i915;
>  	int ret;
>  
> +	ret = sanity_check_mmio_access(uncore);
> +	if (ret)
> +		return ret;
> +
>  	/*
>  	 * The boot firmware initializes local memory and assesses its health.
>  	 * If memory training fails, the punit will have been instructed to
> -- 
> 2.39.2
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation

Re: [Intel-gfx] [PATCH v2 1/2] drm/i915: Sanitycheck MMIO access early in driver load

[Andi Shyti]

Hi Matt,

> > We occasionally see the PCI device in a non-accessible state at the
> > point the driver is loaded.  When this happens, all BAR accesses will
> > read back as 0xFFFFFFFF.  Rather than reading registers and
> > misinterpreting their (invalid) values, let's specifically check for
> > 0xFFFFFFFF in a register that cannot have that value to see if the
> > device is accessible.
> > 
> > Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> > Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> > Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_uncore.c | 35 +++++++++++++++++++++++++++++
> >  1 file changed, 35 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> > index e1e1f34490c8e..0b69081d6d285 100644
> > --- a/drivers/gpu/drm/i915/intel_uncore.c
> > +++ b/drivers/gpu/drm/i915/intel_uncore.c
> > @@ -2602,11 +2602,46 @@ static int uncore_forcewake_init(struct intel_uncore *uncore)
> >  	return 0;
> >  }
> >  
> > +static int sanity_check_mmio_access(struct intel_uncore *uncore)
> > +{
> > +	struct drm_i915_private *i915 = uncore->i915;
> > +	int ret;
> > +
> > +	if (GRAPHICS_VER(i915) < 8)
> > +		return 0;
> > +
> > +	/*
> > +	 * Sanitycheck that MMIO access to the device is working properly.  If
> > +	 * the CPU is unable to communcate with a PCI device, BAR reads will
> > +	 * return 0xFFFFFFFF.  Let's make sure the device isn't in this state
> > +	 * before we start trying to access registers.
> > +	 *
> > +	 * We use the primary GT's forcewake register as our guinea pig since
> > +	 * it's been around since HSW and it's a masked register so the upper
> > +	 * 16 bits can never read back as 1's if device access is operating
> > +	 * properly.
> > +	 *
> > +	 * If MMIO isn't working, we'll wait up to 2 seconds to see if it
> > +	 * recovers, then give up.
> > +	 */
> > +	ret = intel_wait_for_register_fw(uncore, FORCEWAKE_MT, 0, 0, 2000000);
> 
> It looks like you lost the check for 0xFFFFFFFF specifically.  In fact
> with a mask/value of 0, isn't this always going to just always pass
> immediately?

uh... yes... sorry, I just got confused and lost track of the
goal of the patch.

Sorry, then please ignore... I don't see then how
intel_wait_for_register_fw() can be used with a '!='.

Please, ignore this v2.

Thanks and sorry, again,
Andi

> We don't know what the value of this register will be (there may or may
> not be some bits set), but we need to make sure that it isn't 0xFFFFFFFF
> because that means we're not even truly accessing the register, just
> hitting a PCI BAR read failure.
> 
> 
> Matt
> 
> > +	if (ret == -ETIMEDOUT) {
> > +		drm_err(&i915->drm, "Device is non-operational; MMIO access returns 0xFFFFFFFF!\n");
> > +		return -EIO;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >  int intel_uncore_init_mmio(struct intel_uncore *uncore)
> >  {
> >  	struct drm_i915_private *i915 = uncore->i915;
> >  	int ret;
> >  
> > +	ret = sanity_check_mmio_access(uncore);
> > +	if (ret)
> > +		return ret;
> > +
> >  	/*
> >  	 * The boot firmware initializes local memory and assesses its health.
> >  	 * If memory training fails, the punit will have been instructed to
> > -- 
> > 2.39.2
> > 
> 
> -- 
> Matt Roper
> Graphics Software Engineer
> Linux GPU Platform Enablement
> Intel Corporation

[Intel-gfx] ✓ Fi.CI.IGT: success for Report MMIO communication problems more clearly (rev2)

[Patchwork]

[-- Attachment #1: Type: text/plain, Size: 23269 bytes --]

== Series Details ==

Series: Report MMIO communication problems more clearly (rev2)
URL   : https://patchwork.freedesktop.org/series/115421/
State : success

== Summary ==

CI Bug Log - changes from CI_DRM_12890_full -> Patchwork_115421v2_full
====================================================

Summary
-------

  **SUCCESS**

  No regressions found.

  

Participating hosts (8 -> 7)
------------------------------

  Missing    (1): shard-rkl0 

Possible new issues
-------------------

  Here are the unknown changes that may have been introduced in Patchwork_115421v2_full:

### IGT changes ###

#### Suppressed ####

  The following results come from untrusted machines, tests, or statuses.
  They do not affect the overall result.

  * igt@i915_pm_rps@min-max-config-idle:
    - {shard-dg1}:        NOTRUN -> [FAIL][1]
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-dg1-17/igt@i915_pm_rps@min-max-config-idle.html

  * igt@kms_cursor_legacy@forked-bo@pipe-b:
    - {shard-rkl}:        NOTRUN -> [INCOMPLETE][2]
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-6/igt@kms_cursor_legacy@forked-bo@pipe-b.html

  
Known issues
------------

  Here are the changes found in Patchwork_115421v2_full that come from known issues:

### IGT changes ###

#### Issues hit ####

  * igt@gem_lmem_swapping@heavy-multi:
    - shard-glk:          NOTRUN -> [SKIP][3] ([fdo#109271] / [i915#4613])
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-glk1/igt@gem_lmem_swapping@heavy-multi.html

  * igt@gem_ppgtt@flink-and-close-vma-leak:
    - shard-glk:          [PASS][4] -> [FAIL][5] ([i915#644])
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-glk3/igt@gem_ppgtt@flink-and-close-vma-leak.html
   [5]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-glk1/igt@gem_ppgtt@flink-and-close-vma-leak.html

  * igt@kms_ccs@pipe-c-random-ccs-data-y_tiled_gen12_rc_ccs_cc:
    - shard-glk:          NOTRUN -> [SKIP][6] ([fdo#109271] / [i915#3886]) +1 similar issue
   [6]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-glk1/igt@kms_ccs@pipe-c-random-ccs-data-y_tiled_gen12_rc_ccs_cc.html

  * igt@kms_ccs@pipe-d-bad-pixel-format-yf_tiled_ccs:
    - shard-glk:          NOTRUN -> [SKIP][7] ([fdo#109271]) +23 similar issues
   [7]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-glk1/igt@kms_ccs@pipe-d-bad-pixel-format-yf_tiled_ccs.html

  * igt@kms_cursor_legacy@2x-long-flip-vs-cursor-legacy:
    - shard-glk:          [PASS][8] -> [FAIL][9] ([i915#72])
   [8]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-glk9/igt@kms_cursor_legacy@2x-long-flip-vs-cursor-legacy.html
   [9]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-glk4/igt@kms_cursor_legacy@2x-long-flip-vs-cursor-legacy.html

  * igt@kms_cursor_legacy@flip-vs-cursor-atomic-transitions-varying-size:
    - shard-apl:          [PASS][10] -> [FAIL][11] ([i915#2346]) +1 similar issue
   [10]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-apl2/igt@kms_cursor_legacy@flip-vs-cursor-atomic-transitions-varying-size.html
   [11]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-apl6/igt@kms_cursor_legacy@flip-vs-cursor-atomic-transitions-varying-size.html

  
#### Possible fixes ####

  * igt@drm_fdinfo@most-busy-check-all@rcs0:
    - {shard-rkl}:        [FAIL][12] ([i915#7742]) -> [PASS][13]
   [12]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-6/igt@drm_fdinfo@most-busy-check-all@rcs0.html
   [13]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-2/igt@drm_fdinfo@most-busy-check-all@rcs0.html

  * igt@fbdev@eof:
    - {shard-rkl}:        [SKIP][14] ([i915#2582]) -> [PASS][15] +1 similar issue
   [14]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-5/igt@fbdev@eof.html
   [15]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-6/igt@fbdev@eof.html

  * igt@fbdev@unaligned-write:
    - {shard-tglu}:       [SKIP][16] ([i915#2582]) -> [PASS][17]
   [16]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-tglu-9/igt@fbdev@unaligned-write.html
   [17]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-tglu-4/igt@fbdev@unaligned-write.html

  * igt@gem_eio@in-flight-external:
    - {shard-rkl}:        [ABORT][18] ([i915#7811]) -> [PASS][19]
   [18]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-3/igt@gem_eio@in-flight-external.html
   [19]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-3/igt@gem_eio@in-flight-external.html

  * igt@gem_eio@reset-stress:
    - {shard-dg1}:        [FAIL][20] ([i915#5784]) -> [PASS][21]
   [20]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-dg1-12/igt@gem_eio@reset-stress.html
   [21]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-dg1-18/igt@gem_eio@reset-stress.html

  * igt@gem_exec_fair@basic-deadline:
    - shard-glk:          [FAIL][22] ([i915#2846]) -> [PASS][23]
   [22]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-glk6/igt@gem_exec_fair@basic-deadline.html
   [23]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-glk5/igt@gem_exec_fair@basic-deadline.html

  * igt@gem_exec_reloc@basic-write-gtt-noreloc:
    - {shard-rkl}:        [SKIP][24] ([i915#3281]) -> [PASS][25] +1 similar issue
   [24]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-1/igt@gem_exec_reloc@basic-write-gtt-noreloc.html
   [25]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-5/igt@gem_exec_reloc@basic-write-gtt-noreloc.html

  * igt@gem_exec_suspend@basic-s4-devices@lmem0:
    - {shard-dg1}:        [ABORT][26] ([i915#7975]) -> [PASS][27]
   [26]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-dg1-14/igt@gem_exec_suspend@basic-s4-devices@lmem0.html
   [27]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-dg1-15/igt@gem_exec_suspend@basic-s4-devices@lmem0.html

  * igt@gem_exec_suspend@basic-s4-devices@smem:
    - {shard-tglu}:       [ABORT][28] ([i915#7975]) -> [PASS][29]
   [28]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-tglu-10/igt@gem_exec_suspend@basic-s4-devices@smem.html
   [29]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-tglu-9/igt@gem_exec_suspend@basic-s4-devices@smem.html

  * igt@gem_partial_pwrite_pread@reads:
    - {shard-rkl}:        [SKIP][30] ([i915#3282]) -> [PASS][31] +4 similar issues
   [30]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-3/igt@gem_partial_pwrite_pread@reads.html
   [31]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-5/igt@gem_partial_pwrite_pread@reads.html

  * igt@gen9_exec_parse@allowed-single:
    - shard-glk:          [ABORT][32] ([i915#5566]) -> [PASS][33]
   [32]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-glk6/igt@gen9_exec_parse@allowed-single.html
   [33]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-glk1/igt@gen9_exec_parse@allowed-single.html

  * igt@gen9_exec_parse@secure-batches:
    - {shard-rkl}:        [SKIP][34] ([i915#2527]) -> [PASS][35]
   [34]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-1/igt@gen9_exec_parse@secure-batches.html
   [35]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-5/igt@gen9_exec_parse@secure-batches.html

  * igt@i915_hangman@gt-engine-error@bcs0:
    - {shard-rkl}:        [SKIP][36] ([i915#6258]) -> [PASS][37]
   [36]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-5/igt@i915_hangman@gt-engine-error@bcs0.html
   [37]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-2/igt@i915_hangman@gt-engine-error@bcs0.html

  * igt@i915_pm_dc@dc5-dpms:
    - {shard-rkl}:        [FAIL][38] ([i915#7330]) -> [PASS][39]
   [38]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-5/igt@i915_pm_dc@dc5-dpms.html
   [39]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-3/igt@i915_pm_dc@dc5-dpms.html

  * igt@i915_pm_rpm@dpms-lpsp:
    - {shard-rkl}:        [SKIP][40] ([i915#1397]) -> [PASS][41]
   [40]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-5/igt@i915_pm_rpm@dpms-lpsp.html
   [41]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-6/igt@i915_pm_rpm@dpms-lpsp.html

  * igt@i915_pm_rpm@dpms-mode-unset-lpsp:
    - {shard-dg1}:        [SKIP][42] ([i915#1397]) -> [PASS][43] +1 similar issue
   [42]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-dg1-13/igt@i915_pm_rpm@dpms-mode-unset-lpsp.html
   [43]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-dg1-14/igt@i915_pm_rpm@dpms-mode-unset-lpsp.html

  * igt@i915_pm_rpm@modeset-lpsp-stress-no-wait:
    - {shard-tglu}:       [SKIP][44] ([i915#1397]) -> [PASS][45]
   [44]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-tglu-9/igt@i915_pm_rpm@modeset-lpsp-stress-no-wait.html
   [45]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-tglu-7/igt@i915_pm_rpm@modeset-lpsp-stress-no-wait.html

  * {igt@i915_power@sanity}:
    - {shard-rkl}:        [SKIP][46] ([i915#7984]) -> [PASS][47]
   [46]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-3/igt@i915_power@sanity.html
   [47]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-5/igt@i915_power@sanity.html

  * igt@kms_big_fb@x-tiled-32bpp-rotate-0:
    - {shard-rkl}:        [SKIP][48] ([i915#1845] / [i915#4098]) -> [PASS][49] +18 similar issues
   [48]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-1/igt@kms_big_fb@x-tiled-32bpp-rotate-0.html
   [49]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-6/igt@kms_big_fb@x-tiled-32bpp-rotate-0.html

  * igt@kms_ccs@pipe-c-crc-primary-rotation-180-y_tiled_gen12_rc_ccs:
    - {shard-tglu}:       [SKIP][50] ([i915#1845]) -> [PASS][51] +14 similar issues
   [50]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-tglu-10/igt@kms_ccs@pipe-c-crc-primary-rotation-180-y_tiled_gen12_rc_ccs.html
   [51]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-tglu-7/igt@kms_ccs@pipe-c-crc-primary-rotation-180-y_tiled_gen12_rc_ccs.html

  * igt@kms_frontbuffer_tracking@fbc-1p-indfb-fliptrack-mmap-gtt:
    - {shard-tglu}:       [SKIP][52] ([i915#1849]) -> [PASS][53] +14 similar issues
   [52]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-tglu-9/igt@kms_frontbuffer_tracking@fbc-1p-indfb-fliptrack-mmap-gtt.html
   [53]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-tglu-7/igt@kms_frontbuffer_tracking@fbc-1p-indfb-fliptrack-mmap-gtt.html

  * igt@kms_frontbuffer_tracking@psr-1p-primscrn-cur-indfb-move:
    - {shard-rkl}:        [SKIP][54] ([i915#1849] / [i915#4098]) -> [PASS][55] +7 similar issues
   [54]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-5/igt@kms_frontbuffer_tracking@psr-1p-primscrn-cur-indfb-move.html
   [55]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-6/igt@kms_frontbuffer_tracking@psr-1p-primscrn-cur-indfb-move.html

  * igt@kms_psr@sprite_mmap_cpu:
    - {shard-rkl}:        [SKIP][56] ([i915#1072]) -> [PASS][57] +1 similar issue
   [56]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-5/igt@kms_psr@sprite_mmap_cpu.html
   [57]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-6/igt@kms_psr@sprite_mmap_cpu.html

  * igt@kms_pwrite_crc:
    - {shard-tglu}:       [SKIP][58] ([fdo#109274] / [i915#1845]) -> [PASS][59]
   [58]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-tglu-9/igt@kms_pwrite_crc.html
   [59]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-tglu-7/igt@kms_pwrite_crc.html

  * igt@kms_vblank@pipe-c-wait-forked:
    - {shard-tglu}:       [SKIP][60] ([i915#1845] / [i915#7651]) -> [PASS][61] +31 similar issues
   [60]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-tglu-9/igt@kms_vblank@pipe-c-wait-forked.html
   [61]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-tglu-7/igt@kms_vblank@pipe-c-wait-forked.html

  * igt@prime_vgem@basic-read:
    - {shard-rkl}:        [SKIP][62] ([fdo#109295] / [i915#3291] / [i915#3708]) -> [PASS][63]
   [62]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_12890/shard-rkl-1/igt@prime_vgem@basic-read.html
   [63]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/shard-rkl-5/igt@prime_vgem@basic-read.html

  
  {name}: This element is suppressed. This means it is ignored when computing
          the status of the difference (SUCCESS, WARNING, or FAILURE).

  [fdo#109271]: https://bugs.freedesktop.org/show_bug.cgi?id=109271
  [fdo#109274]: https://bugs.freedesktop.org/show_bug.cgi?id=109274
  [fdo#109280]: https://bugs.freedesktop.org/show_bug.cgi?id=109280
  [fdo#109285]: https://bugs.freedesktop.org/show_bug.cgi?id=109285
  [fdo#109289]: https://bugs.freedesktop.org/show_bug.cgi?id=109289
  [fdo#109295]: https://bugs.freedesktop.org/show_bug.cgi?id=109295
  [fdo#109308]: https://bugs.freedesktop.org/show_bug.cgi?id=109308
  [fdo#109315]: https://bugs.freedesktop.org/show_bug.cgi?id=109315
  [fdo#110189]: https://bugs.freedesktop.org/show_bug.cgi?id=110189
  [fdo#110723]: https://bugs.freedesktop.org/show_bug.cgi?id=110723
  [fdo#111068]: https://bugs.freedesktop.org/show_bug.cgi?id=111068
  [fdo#111614]: https://bugs.freedesktop.org/show_bug.cgi?id=111614
  [fdo#111615]: https://bugs.freedesktop.org/show_bug.cgi?id=111615
  [fdo#111656]: https://bugs.freedesktop.org/show_bug.cgi?id=111656
  [fdo#111825]: https://bugs.freedesktop.org/show_bug.cgi?id=111825
  [fdo#111827]: https://bugs.freedesktop.org/show_bug.cgi?id=111827
  [fdo#112054]: https://bugs.freedesktop.org/show_bug.cgi?id=112054
  [fdo#112283]: https://bugs.freedesktop.org/show_bug.cgi?id=112283
  [i915#1072]: https://gitlab.freedesktop.org/drm/intel/issues/1072
  [i915#1257]: https://gitlab.freedesktop.org/drm/intel/issues/1257
  [i915#132]: https://gitlab.freedesktop.org/drm/intel/issues/132
  [i915#1397]: https://gitlab.freedesktop.org/drm/intel/issues/1397
  [i915#1769]: https://gitlab.freedesktop.org/drm/intel/issues/1769
  [i915#1825]: https://gitlab.freedesktop.org/drm/intel/issues/1825
  [i915#1845]: https://gitlab.freedesktop.org/drm/intel/issues/1845
  [i915#1849]: https://gitlab.freedesktop.org/drm/intel/issues/1849
  [i915#2232]: https://gitlab.freedesktop.org/drm/intel/issues/2232
  [i915#2346]: https://gitlab.freedesktop.org/drm/intel/issues/2346
  [i915#2437]: https://gitlab.freedesktop.org/drm/intel/issues/2437
  [i915#2527]: https://gitlab.freedesktop.org/drm/intel/issues/2527
  [i915#2575]: https://gitlab.freedesktop.org/drm/intel/issues/2575
  [i915#2582]: https://gitlab.freedesktop.org/drm/intel/issues/2582
  [i915#2587]: https://gitlab.freedesktop.org/drm/intel/issues/2587
  [i915#2658]: https://gitlab.freedesktop.org/drm/intel/issues/2658
  [i915#2672]: https://gitlab.freedesktop.org/drm/intel/issues/2672
  [i915#2681]: https://gitlab.freedesktop.org/drm/intel/issues/2681
  [i915#2705]: https://gitlab.freedesktop.org/drm/intel/issues/2705
  [i915#2842]: https://gitlab.freedesktop.org/drm/intel/issues/2842
  [i915#2846]: https://gitlab.freedesktop.org/drm/intel/issues/2846
  [i915#2920]: https://gitlab.freedesktop.org/drm/intel/issues/2920
  [i915#3116]: https://gitlab.freedesktop.org/drm/intel/issues/3116
  [i915#315]: https://gitlab.freedesktop.org/drm/intel/issues/315
  [i915#3281]: https://gitlab.freedesktop.org/drm/intel/issues/3281
  [i915#3282]: https://gitlab.freedesktop.org/drm/intel/issues/3282
  [i915#3291]: https://gitlab.freedesktop.org/drm/intel/issues/3291
  [i915#3297]: https://gitlab.freedesktop.org/drm/intel/issues/3297
  [i915#3299]: https://gitlab.freedesktop.org/drm/intel/issues/3299
  [i915#3318]: https://gitlab.freedesktop.org/drm/intel/issues/3318
  [i915#3359]: https://gitlab.freedesktop.org/drm/intel/issues/3359
  [i915#3361]: https://gitlab.freedesktop.org/drm/intel/issues/3361
  [i915#3458]: https://gitlab.freedesktop.org/drm/intel/issues/3458
  [i915#3539]: https://gitlab.freedesktop.org/drm/intel/issues/3539
  [i915#3546]: https://gitlab.freedesktop.org/drm/intel/issues/3546
  [i915#3547]: https://gitlab.freedesktop.org/drm/intel/issues/3547
  [i915#3555]: https://gitlab.freedesktop.org/drm/intel/issues/3555
  [i915#3591]: https://gitlab.freedesktop.org/drm/intel/issues/3591
  [i915#3637]: https://gitlab.freedesktop.org/drm/intel/issues/3637
  [i915#3638]: https://gitlab.freedesktop.org/drm/intel/issues/3638
  [i915#3639]: https://gitlab.freedesktop.org/drm/intel/issues/3639
  [i915#3689]: https://gitlab.freedesktop.org/drm/intel/issues/3689
  [i915#3708]: https://gitlab.freedesktop.org/drm/intel/issues/3708
  [i915#3734]: https://gitlab.freedesktop.org/drm/intel/issues/3734
  [i915#3840]: https://gitlab.freedesktop.org/drm/intel/issues/3840
  [i915#3886]: https://gitlab.freedesktop.org/drm/intel/issues/3886
  [i915#3936]: https://gitlab.freedesktop.org/drm/intel/issues/3936
  [i915#3952]: https://gitlab.freedesktop.org/drm/intel/issues/3952
  [i915#3955]: https://gitlab.freedesktop.org/drm/intel/issues/3955
  [i915#4036]: https://gitlab.freedesktop.org/drm/intel/issues/4036
  [i915#404]: https://gitlab.freedesktop.org/drm/intel/issues/404
  [i915#4070]: https://gitlab.freedesktop.org/drm/intel/issues/4070
  [i915#4077]: https://gitlab.freedesktop.org/drm/intel/issues/4077
  [i915#4078]: https://gitlab.freedesktop.org/drm/intel/issues/4078
  [i915#4083]: https://gitlab.freedesktop.org/drm/intel/issues/4083
  [i915#4098]: https://gitlab.freedesktop.org/drm/intel/issues/4098
  [i915#4103]: https://gitlab.freedesktop.org/drm/intel/issues/4103
  [i915#4213]: https://gitlab.freedesktop.org/drm/intel/issues/4213
  [i915#4215]: https://gitlab.freedesktop.org/drm/intel/issues/4215
  [i915#4270]: https://gitlab.freedesktop.org/drm/intel/issues/4270
  [i915#4349]: https://gitlab.freedesktop.org/drm/intel/issues/4349
  [i915#4525]: https://gitlab.freedesktop.org/drm/intel/issues/4525
  [i915#4538]: https://gitlab.freedesktop.org/drm/intel/issues/4538
  [i915#4565]: https://gitlab.freedesktop.org/drm/intel/issues/4565
  [i915#4579]: https://gitlab.freedesktop.org/drm/intel/issues/4579
  [i915#4613]: https://gitlab.freedesktop.org/drm/intel/issues/4613
  [i915#4812]: https://gitlab.freedesktop.org/drm/intel/issues/4812
  [i915#4833]: https://gitlab.freedesktop.org/drm/intel/issues/4833
  [i915#4852]: https://gitlab.freedesktop.org/drm/intel/issues/4852
  [i915#4859]: https://gitlab.freedesktop.org/drm/intel/issues/4859
  [i915#4860]: https://gitlab.freedesktop.org/drm/intel/issues/4860
  [i915#4880]: https://gitlab.freedesktop.org/drm/intel/issues/4880
  [i915#4884]: https://gitlab.freedesktop.org/drm/intel/issues/4884
  [i915#4885]: https://gitlab.freedesktop.org/drm/intel/issues/4885
  [i915#5176]: https://gitlab.freedesktop.org/drm/intel/issues/5176
  [i915#5235]: https://gitlab.freedesktop.org/drm/intel/issues/5235
  [i915#5286]: https://gitlab.freedesktop.org/drm/intel/issues/5286
  [i915#5288]: https://gitlab.freedesktop.org/drm/intel/issues/5288
  [i915#5289]: https://gitlab.freedesktop.org/drm/intel/issues/5289
  [i915#5325]: https://gitlab.freedesktop.org/drm/intel/issues/5325
  [i915#533]: https://gitlab.freedesktop.org/drm/intel/issues/533
  [i915#5354]: https://gitlab.freedesktop.org/drm/intel/issues/5354
  [i915#5439]: https://gitlab.freedesktop.org/drm/intel/issues/5439
  [i915#5461]: https://gitlab.freedesktop.org/drm/intel/issues/5461
  [i915#5563]: https://gitlab.freedesktop.org/drm/intel/issues/5563
  [i915#5566]: https://gitlab.freedesktop.org/drm/intel/issues/5566
  [i915#5784]: https://gitlab.freedesktop.org/drm/intel/issues/5784
  [i915#6095]: https://gitlab.freedesktop.org/drm/intel/issues/6095
  [i915#6247]: https://gitlab.freedesktop.org/drm/intel/issues/6247
  [i915#6248]: https://gitlab.freedesktop.org/drm/intel/issues/6248
  [i915#6258]: https://gitlab.freedesktop.org/drm/intel/issues/6258
  [i915#6268]: https://gitlab.freedesktop.org/drm/intel/issues/6268
  [i915#6301]: https://gitlab.freedesktop.org/drm/intel/issues/6301
  [i915#6334]: https://gitlab.freedesktop.org/drm/intel/issues/6334
  [i915#6433]: https://gitlab.freedesktop.org/drm/intel/issues/6433
  [i915#644]: https://gitlab.freedesktop.org/drm/intel/issues/644
  [i915#6497]: https://gitlab.freedesktop.org/drm/intel/issues/6497
  [i915#6524]: https://gitlab.freedesktop.org/drm/intel/issues/6524
  [i915#658]: https://gitlab.freedesktop.org/drm/intel/issues/658
  [i915#6768]: https://gitlab.freedesktop.org/drm/intel/issues/6768
  [i915#6944]: https://gitlab.freedesktop.org/drm/intel/issues/6944
  [i915#6946]: https://gitlab.freedesktop.org/drm/intel/issues/6946
  [i915#6953]: https://gitlab.freedesktop.org/drm/intel/issues/6953
  [i915#7037]: https://gitlab.freedesktop.org/drm/intel/issues/7037
  [i915#7116]: https://gitlab.freedesktop.org/drm/intel/issues/7116
  [i915#7118]: https://gitlab.freedesktop.org/drm/intel/issues/7118
  [i915#7128]: https://gitlab.freedesktop.org/drm/intel/issues/7128
  [i915#7178]: https://gitlab.freedesktop.org/drm/intel/issues/7178
  [i915#72]: https://gitlab.freedesktop.org/drm/intel/issues/72
  [i915#7294]: https://gitlab.freedesktop.org/drm/intel/issues/7294
  [i915#7330]: https://gitlab.freedesktop.org/drm/intel/issues/7330
  [i915#7561]: https://gitlab.freedesktop.org/drm/intel/issues/7561
  [i915#7651]: https://gitlab.freedesktop.org/drm/intel/issues/7651
  [i915#7697]: https://gitlab.freedesktop.org/drm/intel/issues/7697
  [i915#7711]: https://gitlab.freedesktop.org/drm/intel/issues/7711
  [i915#7742]: https://gitlab.freedesktop.org/drm/intel/issues/7742
  [i915#7811]: https://gitlab.freedesktop.org/drm/intel/issues/7811
  [i915#7828]: https://gitlab.freedesktop.org/drm/intel/issues/7828
  [i915#7949]: https://gitlab.freedesktop.org/drm/intel/issues/7949
  [i915#7957]: https://gitlab.freedesktop.org/drm/intel/issues/7957
  [i915#7975]: https://gitlab.freedesktop.org/drm/intel/issues/7975
  [i915#7984]: https://gitlab.freedesktop.org/drm/intel/issues/7984
  [i915#8152]: https://gitlab.freedesktop.org/drm/intel/issues/8152
  [i915#8154]: https://gitlab.freedesktop.org/drm/intel/issues/8154
  [i915#8211]: https://gitlab.freedesktop.org/drm/intel/issues/8211
  [i915#8228]: https://gitlab.freedesktop.org/drm/intel/issues/8228
  [i915#8247]: https://gitlab.freedesktop.org/drm/intel/issues/8247
  [i915#8282]: https://gitlab.freedesktop.org/drm/intel/issues/8282


Build changes
-------------

  * Linux: CI_DRM_12890 -> Patchwork_115421v2

  CI-20190529: 20190529
  CI_DRM_12890: d4834b54c9207f50e07560f1be732a626a1f4bca @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_7210: 5f7116708590b55864456acd993ecdb02374a06f @ https://gitlab.freedesktop.org/drm/igt-gpu-tools.git
  Patchwork_115421v2: d4834b54c9207f50e07560f1be732a626a1f4bca @ git://anongit.freedesktop.org/gfx-ci/linux
  piglit_4509: fdc5a4ca11124ab8413c7988896eec4c97336694 @ git://anongit.freedesktop.org/piglit

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_115421v2/index.html

[-- Attachment #2: Type: text/html, Size: 17512 bytes --]

Re: [Intel-gfx] [PATCH v2 1/2] drm/i915: Sanitycheck MMIO access early in driver load

[Andrzej Hajda]

On 21.03.2023 23:43, Andi Shyti wrote:
> Hi Matt,
> 
>>> We occasionally see the PCI device in a non-accessible state at the
>>> point the driver is loaded.  When this happens, all BAR accesses will
>>> read back as 0xFFFFFFFF.  Rather than reading registers and
>>> misinterpreting their (invalid) values, let's specifically check for
>>> 0xFFFFFFFF in a register that cannot have that value to see if the
>>> device is accessible.
>>>
>>> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
>>> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
>>> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
>>> ---
>>>   drivers/gpu/drm/i915/intel_uncore.c | 35 +++++++++++++++++++++++++++++
>>>   1 file changed, 35 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
>>> index e1e1f34490c8e..0b69081d6d285 100644
>>> --- a/drivers/gpu/drm/i915/intel_uncore.c
>>> +++ b/drivers/gpu/drm/i915/intel_uncore.c
>>> @@ -2602,11 +2602,46 @@ static int uncore_forcewake_init(struct intel_uncore *uncore)
>>>   	return 0;
>>>   }
>>>   
>>> +static int sanity_check_mmio_access(struct intel_uncore *uncore)
>>> +{
>>> +	struct drm_i915_private *i915 = uncore->i915;
>>> +	int ret;
>>> +
>>> +	if (GRAPHICS_VER(i915) < 8)
>>> +		return 0;
>>> +
>>> +	/*
>>> +	 * Sanitycheck that MMIO access to the device is working properly.  If
>>> +	 * the CPU is unable to communcate with a PCI device, BAR reads will
>>> +	 * return 0xFFFFFFFF.  Let's make sure the device isn't in this state
>>> +	 * before we start trying to access registers.
>>> +	 *
>>> +	 * We use the primary GT's forcewake register as our guinea pig since
>>> +	 * it's been around since HSW and it's a masked register so the upper
>>> +	 * 16 bits can never read back as 1's if device access is operating
>>> +	 * properly.


Maybe we can just check upper 16bits then. Sth like:
ret = intel_wait_for_register_fw(uncore, FORCEWAKE_MT, GENMASK(31, 16), 
0, 2000000);

Regards
Andrzej

>>> +	 *
>>> +	 * If MMIO isn't working, we'll wait up to 2 seconds to see if it
>>> +	 * recovers, then give up.
>>> +	 */
>>> +	ret = intel_wait_for_register_fw(uncore, FORCEWAKE_MT, 0, 0, 2000000);
>>
>> It looks like you lost the check for 0xFFFFFFFF specifically.  In fact
>> with a mask/value of 0, isn't this always going to just always pass
>> immediately?
> 
> uh... yes... sorry, I just got confused and lost track of the
> goal of the patch.
> 
> Sorry, then please ignore... I don't see then how
> intel_wait_for_register_fw() can be used with a '!='.
> 
> Please, ignore this v2.
> 
> Thanks and sorry, again,
> Andi
> 
>> We don't know what the value of this register will be (there may or may
>> not be some bits set), but we need to make sure that it isn't 0xFFFFFFFF
>> because that means we're not even truly accessing the register, just
>> hitting a PCI BAR read failure.
>>
>>
>> Matt
>>
>>> +	if (ret == -ETIMEDOUT) {
>>> +		drm_err(&i915->drm, "Device is non-operational; MMIO access returns 0xFFFFFFFF!\n");
>>> +		return -EIO;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>>   int intel_uncore_init_mmio(struct intel_uncore *uncore)
>>>   {
>>>   	struct drm_i915_private *i915 = uncore->i915;
>>>   	int ret;
>>>   
>>> +	ret = sanity_check_mmio_access(uncore);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>>   	/*
>>>   	 * The boot firmware initializes local memory and assesses its health.
>>>   	 * If memory training fails, the punit will have been instructed to
>>> -- 
>>> 2.39.2
>>>
>>
>> -- 
>> Matt Roper
>> Graphics Software Engineer
>> Linux GPU Platform Enablement
>> Intel Corporation

Re: [Intel-gfx] [PATCH v2 2/2] drm/i915: Check for unreliable MMIO during forcewake

[Andrzej Hajda]

On 21.03.2023 18:09, Andi Shyti wrote:
> From: Matt Roper <matthew.d.roper@intel.com>
> 
> Although we now sanitycheck MMIO access during driver load to make sure
> the MMIO BAR isn't returning all 0xFFFFFFFF, there have been a few cases
> where (temporarily?) unreliable MMIO access has happened after GPU
> resets or power events.  We'll often notice this on our next GT register
> access since forcewake handling will fail; let's change our handling
> slightly so that when this happens we print a more meaningful message
> clarifying that the problem is the MMIO access, not forcewake
> specifically.
> 
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
> ---
>   drivers/gpu/drm/i915/intel_uncore.c | 12 +++++++++---
>   1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index 0b69081d6d285..303a5d38c93a5 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -178,9 +178,15 @@ static inline void
>   fw_domain_wait_ack_clear(const struct intel_uncore_forcewake_domain *d)
>   {
>   	if (wait_ack_clear(d, FORCEWAKE_KERNEL)) {
> -		drm_err(&d->uncore->i915->drm,
> -			"%s: timed out waiting for forcewake ack to clear.\n",
> -			intel_uncore_forcewake_domain_to_str(d->id));
> +		if (fw_ack(d) == ~0)
> +			drm_err(&d->uncore->i915->drm,
> +				"%s: MMIO unreliable (forcewake register returns 0xFFFFFFFF)!\n",
> +				intel_uncore_forcewake_domain_to_str(d->id));
> +		else
> +			drm_err(&d->uncore->i915->drm,
> +				"%s: timed out waiting for forcewake ack to clear.\n",
> +				intel_uncore_forcewake_domain_to_str(d->id));
> +
With:

if (!wait_ack_clear(...))
	return;

you do not need to indent.
And since drm_err have the same set of args in both cases, except fmt, 
it could be also simplified.

Anyway I am not sure if it is worth effort, so:
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>

Regards
Andrzej


>   		add_taint_for_CI(d->uncore->i915, TAINT_WARN); /* CI now unreliable */
>   	}
>   }