[Intel-gfx] [PATCH v2] drm/i915/debugfs : PM_REQ and PM_RES registers

[Gupta, Anshuman]

> -----Original Message-----
> From: S, Saichandana <saichandana.s at intel.com>
> Sent: Monday, January 4, 2021 4:01 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: S, Saichandana <saichandana.s at intel.com>; Nikula, Jani
> <jani.nikula at intel.com>; Gupta, Anshuman <anshuman.gupta at intel.com>
> Subject: [PATCH v2] drm/i915/debugfs : PM_REQ and PM_RES registers
> 
> From: Saichandana <saichandana.s at intel.com>
> 
> PM_REQ register provides the value of the last PM request from PCU to
> Display Engine.PM_RES register provides the value of the last PM response
> from Display Engine to PCU.This debugfs will be used by
> DC9 IGT test to know about "DC9 Ready" status.
> 
> B.Spec : 49501, 49502
Please mention here the review comment u had fixed.
So it will be easy for review.
V2:
Added a functional print to debugs. [Keep name of Reviewer]
> 
> Signed-off-by: Saichandana <saichandana.s at intel.com>
> ---
>  .../drm/i915/display/intel_display_debugfs.c  | 30
> +++++++++++++++++++
>  drivers/gpu/drm/i915/i915_reg.h               |  8 +++++
>  2 files changed, 38 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> index cd7e5519ee7d..551fb1a90bb3 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -559,6 +559,36 @@ static int i915_dmc_info(struct seq_file *m, void
> *unused)
>  	return 0;
>  }
> 
> +static int i915_pm_req_res_info(struct seq_file *m, void *unused) {
> +	struct drm_i915_private *dev_priv = node_to_i915(m->private);
> +	struct intel_csr *csr = &dev_priv->csr;
> +	const char *status;
> +
> +	if (!HAS_CSR(dev_priv))
> +		return -ENODEV;
> +	if (!csr->dmc_payload)
> +		return 0;
> +	seq_printf(m, "PM debug request 0 (0x45284): 0x%08x\n",
> +		   intel_de_read(dev_priv, PM_REQ_DBG_0));
> +	seq_printf(m, "PM debug request 1 (0x45288): 0x%08x\n",
> +		   intel_de_read(dev_priv, PM_REQ_DBG_1));
> +	seq_printf(m, "PM debug response 0 (0x4528C): 0x%08x\n",
> +		   intel_de_read(dev_priv, PM_RSP_DBG_0));
> +	seq_printf(m, "PM debug response 1 (0x45290): 0x%08x\n",
> +		   intel_de_read(dev_priv, PM_RSP_DBG_1));
> +	status = (intel_de_read(dev_priv, PM_RSP_DBG_1) &
> MASK_DC9_BIT) ?
> +"yes" : "no";
You don't need to read the value of register again , please store in a variable
And use that value.
Thanks,
Anshuman Gupta.
> +
> +	seq_printf(m, "Time to Next Fill = 0x%0x\n",
> +		   (intel_de_read(dev_priv, PM_RSP_DBG_0) &
> ~MASK_RSP_0));
> +	seq_printf(m, "Time to Next VBI = 0x%0x\n",
> +		   ((intel_de_read(dev_priv, PM_RSP_DBG_0) &
> MASK_RSP_0)) >> 16);
> +	seq_printf(m, "Selective Exit Latency = 0x%0x\n",
> +		   (intel_de_read(dev_priv, PM_RSP_DBG_1) &
> MASK_RSP_1));
> +	seq_printf(m, "DC9 Ready = %s\n", status);
> +	return 0;
> +}
> +
>  static void intel_seq_print_mode(struct seq_file *m, int tabs,
>  				 const struct drm_display_mode *mode)  {
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h index 0023c023f472..3e9ed555f928
> 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -371,6 +371,14 @@ static inline bool
> i915_mmio_reg_valid(i915_reg_t reg)
>  #define VLV_G3DCTL		_MMIO(0x9024)
>  #define VLV_GSCKGCTL		_MMIO(0x9028)
> 
> +#define PM_REQ_DBG_0		_MMIO(0x45284)
> +#define PM_REQ_DBG_1		_MMIO(0x45288)
> +#define PM_RSP_DBG_0		_MMIO(0x4528C)
> +#define PM_RSP_DBG_1		_MMIO(0x45290)
> +#define MASK_RSP_0		(0xFFFF << 16)
> +#define MASK_RSP_1		(7 << 0)
> +#define MASK_DC9_BIT		(1 << 17)
> +
>  #define GEN6_MBCTL		_MMIO(0x0907c)
>  #define   GEN6_MBCTL_ENABLE_BOOT_FETCH	(1 << 4)
>  #define   GEN6_MBCTL_CTX_FETCH_NEEDED	(1 << 3)
> --
> 2.17.1