On Thu, Jun 05, 2025 at 01:29:33PM +0300, Jani Nikula wrote:
> Only use the ms granularity wait in snb_pcode_write_timeout(), primarily
> to better align with the xe driver, which also only has the millisecond
> wait.
>
> Use an arbitrary 250 us fast wait before the specified ms wait, and have
> snb_pcode_write() default to 1 ms.
>
> This means snb_pcode_write() and snb_pcode_write_timeout() will always
> be sleeping functions. There should not be any atomic users for pcode
> writes though, and any display code using pcode via xe has already been
> non-atomic. The uncore wait will do a might_sleep() annotation that
> should catch any problems.
>
> Signed-off-by: Jani Nikula <jani.nik...@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.v...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_cdclk.c | 5 ++---
> drivers/gpu/drm/i915/display/intel_display_power_well.c | 3 +--
> drivers/gpu/drm/i915/intel_pcode.c | 5 ++---
> drivers/gpu/drm/i915/intel_pcode.h | 5 ++---
> drivers/gpu/drm/xe/compat-i915-headers/intel_pcode.h | 6 ++----
> 5 files changed, 9 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c
> b/drivers/gpu/drm/i915/display/intel_cdclk.c
> index f0c673e40ce5..7ad506da7d3d 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> @@ -2147,7 +2147,7 @@ static void bxt_set_cdclk(struct intel_display *display,
> */
> ret = snb_pcode_write_timeout(&dev_priv->uncore,
> HSW_PCODE_DE_WRITE_FREQ_REQ,
> - 0x80000000, 150, 2);
> + 0x80000000, 2);
>
> if (ret) {
> drm_err(display->drm,
> @@ -2187,8 +2187,7 @@ static void bxt_set_cdclk(struct intel_display *display,
> */
> ret = snb_pcode_write_timeout(&dev_priv->uncore,
> HSW_PCODE_DE_WRITE_FREQ_REQ,
> - cdclk_config->voltage_level,
> - 150, 2);
> + cdclk_config->voltage_level, 2);
> }
> if (ret) {
> drm_err(display->drm,
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power_well.c
> b/drivers/gpu/drm/i915/display/intel_display_power_well.c
> index 02e3c22be21e..e60f60ddbff7 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power_well.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c
> @@ -485,8 +485,7 @@ static void icl_tc_cold_exit(struct intel_display
> *display)
> int ret, tries = 0;
>
> while (1) {
> - ret = snb_pcode_write_timeout(&i915->uncore,
> ICL_PCODE_EXIT_TCCOLD, 0,
> - 250, 1);
> + ret = snb_pcode_write(&i915->uncore, ICL_PCODE_EXIT_TCCOLD, 0);
> if (ret != -EAGAIN || ++tries == 3)
> break;
> msleep(1);
> diff --git a/drivers/gpu/drm/i915/intel_pcode.c
> b/drivers/gpu/drm/i915/intel_pcode.c
> index 3db2ba439bb5..b7e9b4ee1425 100644
> --- a/drivers/gpu/drm/i915/intel_pcode.c
> +++ b/drivers/gpu/drm/i915/intel_pcode.c
> @@ -110,13 +110,12 @@ int snb_pcode_read(struct intel_uncore *uncore, u32
> mbox, u32 *val, u32 *val1)
> }
>
> int snb_pcode_write_timeout(struct intel_uncore *uncore, u32 mbox, u32 val,
> - int fast_timeout_us, int slow_timeout_ms)
> + int timeout_ms)
> {
> int err;
>
> mutex_lock(&uncore->i915->sb_lock);
> - err = __snb_pcode_rw(uncore, mbox, &val, NULL,
> - fast_timeout_us, slow_timeout_ms, false);
> + err = __snb_pcode_rw(uncore, mbox, &val, NULL, 250, timeout_ms, false);
> mutex_unlock(&uncore->i915->sb_lock);
>
> if (err) {
> diff --git a/drivers/gpu/drm/i915/intel_pcode.h
> b/drivers/gpu/drm/i915/intel_pcode.h
> index 8d2198e29422..401ce27f72d4 100644
> --- a/drivers/gpu/drm/i915/intel_pcode.h
> +++ b/drivers/gpu/drm/i915/intel_pcode.h
> @@ -11,10 +11,9 @@
> struct intel_uncore;
>
> int snb_pcode_read(struct intel_uncore *uncore, u32 mbox, u32 *val, u32
> *val1);
> -int snb_pcode_write_timeout(struct intel_uncore *uncore, u32 mbox, u32 val,
> - int fast_timeout_us, int slow_timeout_ms);
> +int snb_pcode_write_timeout(struct intel_uncore *uncore, u32 mbox, u32 val,
> int timeout_ms);
> #define snb_pcode_write(uncore, mbox, val) \
> - snb_pcode_write_timeout(uncore, mbox, val, 500, 0)
> + snb_pcode_write_timeout((uncore), (mbox), (val), 1)
>
> int skl_pcode_request(struct intel_uncore *uncore, u32 mbox, u32 request,
> u32 reply_mask, u32 reply, int timeout_base_ms);
> diff --git a/drivers/gpu/drm/xe/compat-i915-headers/intel_pcode.h
> b/drivers/gpu/drm/xe/compat-i915-headers/intel_pcode.h
> index a473aa6697d0..32da708680c2 100644
> --- a/drivers/gpu/drm/xe/compat-i915-headers/intel_pcode.h
> +++ b/drivers/gpu/drm/xe/compat-i915-headers/intel_pcode.h
> @@ -10,11 +10,9 @@
> #include "xe_pcode.h"
>
> static inline int
> -snb_pcode_write_timeout(struct intel_uncore *uncore, u32 mbox, u32 val,
> - int fast_timeout_us, int slow_timeout_ms)
> +snb_pcode_write_timeout(struct intel_uncore *uncore, u32 mbox, u32 val, int
> timeout_ms)
> {
> - return xe_pcode_write_timeout(__compat_uncore_to_tile(uncore), mbox,
> val,
> - slow_timeout_ms ?: 1);
> + return xe_pcode_write_timeout(__compat_uncore_to_tile(uncore), mbox,
> val, timeout_ms);
> }
>
> static inline int
> --
> 2.39.5
>
