Re: [Intel-gfx] [PATCH v3] drm/i915/debugfs : PM_REQ and PM_RES registers

Gupta, Anshuman
2021-01-12T14:37:29Z

> -----Original Message-----
> From: S, Saichandana <saichandana.s@intel.com>
> Sent: Tuesday, January 12, 2021 7:04 PM
> To: intel-gfx@lists.freedesktop.org
> Cc: Nikula, Jani <jani.nikula@intel.com>; Gupta, Anshuman
> <anshuman.gupta@intel.com>; S, Saichandana <saichandana.s@intel.com>
> Subject: [PATCH v3] drm/i915/debugfs : PM_REQ and PM_RES registers
>
> PM_REQ register provides the value of the last PM request[Gupta, Anshuman] , response from PCU to
*PM_DBG_{REQ,RSP}*
> 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"
I would rephrase it as "This debugs DC9 Ready but will be used by dc9 igt test .
It will also print the useful debug information from Display Engine to PCU mailbox register"
> status.
> B.Spec : 49501, 49502
>
> V2:
> Added a functional print to debugfs. [Jani Nikula]
>
> V3:
> Used separate variables to store the register values and also used
> REG_GENMASK and REG_BIT for mask preparation. [Anshuman Gupta]
>
> Removed reading of register contents. Replaced local variable with yesno().
> Placed register macros separately, distinguishing from other macros. [Jani
> Nikula]
>
> Signed-off-by: Saichandana S <saichandana.s@intel.com>
> ---
> .../drm/i915/display/intel_display_debugfs.c | 23
> +++++++++++++++++++
> drivers/gpu/drm/i915/i915_reg.h | 10 ++++++++
> 2 files changed, 33 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..e5997debb8e5 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -559,6 +559,28 @@ 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);
Please use i915 as variable as Jani has suggested earlier.
Thanks,
Anshuman.
> + struct intel_csr *csr = &dev_priv->csr;
> + u32 DC9_status;
> +
> + if (!HAS_CSR(dev_priv))
> + return -ENODEV;
> + if (!csr->dmc_payload)
> + return 0;
> + DC9_status = intel_de_read(dev_priv, PM_RSP_DBG_1) &
> +PM_RESP_DC9_READY;
> +
> + seq_printf(m, "Time to Next Fill : 0x%08x\n",
> + intel_de_read(dev_priv, PM_RSP_DBG_0) &
> PM_RESP_TTNF_MASK);
> + seq_printf(m, "Time to Next VBI : 0x%08x\n",
> + (intel_de_read(dev_priv, PM_RSP_DBG_0) &
> PM_RESP_TTNVBI_MASK) >> 16);
> + seq_printf(m, "Selective Exit Latency : 0x%08x\n",
> + intel_de_read(dev_priv, PM_RSP_DBG_1) &
> PM_RESP_SEL_EXIT_LATENCY_MASK);
> + seq_printf(m, "DC9 Ready : %s\n", yesno(DC9_status));
> + return 0;
> +}
> +
> static void intel_seq_print_mode(struct seq_file *m, int tabs,
> const struct drm_display_mode *mode) {
> @@ -2100,6 +2122,7 @@ static const struct drm_info_list
> intel_display_debugfs_list[] = {
> {"i915_edp_psr_status", i915_edp_psr_status, 0},
> {"i915_power_domain_info", i915_power_domain_info, 0},
> {"i915_dmc_info", i915_dmc_info, 0},
> + {"i915_pm_req_res_info", i915_pm_req_res_info, 0},
> {"i915_display_info", i915_display_info, 0},
> {"i915_shared_dplls_info", i915_shared_dplls_info, 0},
> {"i915_dp_mst_info", i915_dp_mst_info, 0}, diff --git
> a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 0023c023f472..8c91d598dc29 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -12423,4 +12423,14 @@ enum skl_power_gate {
> #define TGL_ROOT_DEVICE_SKU_ULX 0x2
> #define TGL_ROOT_DEVICE_SKU_ULT 0x4
>
> +/*These registers are of functional registers for PM debug request and
> response registers*/
> +#define PM_REQ_DBG_0 _MMIO(0x45284)
> +#define PM_REQ_DBG_1 _MMIO(0x45288)
> +#define PM_RSP_DBG_0 _MMIO(0x4528C)
> +#define PM_RESP_TTNF_MASK REG_GENMASK(15,
> 0)
> +#define PM_RESP_TTNVBI_MASK REG_GENMASK(31,
> 16)
> +#define PM_RSP_DBG_1 _MMIO(0x45290)
> +#define PM_RESP_SEL_EXIT_LATENCY_MASK
> REG_GENMASK(2, 0)
> +#define PM_RESP_DC9_READY REG_BIT(15)
> +
> #endif /* _I915_REG_H_ */
> --
> 2.30.0