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[PATCH] drm/i915/lspcon: do not hardcode settle timeout

Giedrius Statkevičius posted 1 patch 1 year, 3 months ago
There is a newer version of this series
drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 3 +--
drivers/gpu/drm/i915/display/intel_lspcon.c       | 2 +-
include/drm/display/drm_dp_dual_mode_helper.h     | 2 +-
3 files changed, 3 insertions(+), 4 deletions(-)
[PATCH] drm/i915/lspcon: do not hardcode settle timeout
Posted by Giedrius Statkevičius 1 year, 3 months ago 
Avoid hardcoding the LSPCON settle timeout because it takes a longer
time on certain chips made by certain vendors. Use the function that
already exists to determine the timeout.

Signed-off-by: Giedrius Statkevičius <giedriuswork@gmail.com>
---
 drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 3 +--
 drivers/gpu/drm/i915/display/intel_lspcon.c       | 2 +-
 include/drm/display/drm_dp_dual_mode_helper.h     | 2 +-
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
index 14a2a8473682..ae9d6b93136b 100644
--- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
@@ -491,11 +491,10 @@ EXPORT_SYMBOL(drm_lspcon_get_mode);
  * 0 on success, -error on failure/timeout
  */
 int drm_lspcon_set_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
-			enum drm_lspcon_mode mode)
+			enum drm_lspcon_mode mode, int time_out)
 {
 	u8 data = 0;
 	int ret;
-	int time_out = 200;
 	enum drm_lspcon_mode current_mode;
 
 	if (mode == DRM_LSPCON_MODE_PCON)
diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.c b/drivers/gpu/drm/i915/display/intel_lspcon.c
index f9db867fae89..764cf4898364 100644
--- a/drivers/gpu/drm/i915/display/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/display/intel_lspcon.c
@@ -211,7 +211,7 @@ static int lspcon_change_mode(struct intel_lspcon *lspcon,
 		return 0;
 	}
 
-	err = drm_lspcon_set_mode(intel_dp->aux.drm_dev, ddc, mode);
+	err = drm_lspcon_set_mode(intel_dp->aux.drm_dev, ddc, mode, lspcon_get_mode_settle_timeout(lspcon));
 	if (err < 0) {
 		drm_err(display->drm, "LSPCON mode change failed\n");
 		return err;
diff --git a/include/drm/display/drm_dp_dual_mode_helper.h b/include/drm/display/drm_dp_dual_mode_helper.h
index 7ee482265087..7ac6969db935 100644
--- a/include/drm/display/drm_dp_dual_mode_helper.h
+++ b/include/drm/display/drm_dp_dual_mode_helper.h
@@ -117,5 +117,5 @@ const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type);
 int drm_lspcon_get_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
 			enum drm_lspcon_mode *current_mode);
 int drm_lspcon_set_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
-			enum drm_lspcon_mode reqd_mode);
+			enum drm_lspcon_mode reqd_mode, int time_out);
 #endif
-- 
2.47.0
Re: [PATCH] drm/i915/lspcon: do not hardcode settle timeout
Posted by Nautiyal, Ankit K 1 year, 3 months ago 
On 10/14/2024 3:09 PM, Giedrius Statkevičius wrote:
> Avoid hardcoding the LSPCON settle timeout because it takes a longer
> time on certain chips made by certain vendors. Use the function that
> already exists to determine the timeout.
>
> Signed-off-by: Giedrius Statkevičius <giedriuswork@gmail.com>
> ---
>   drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 3 +--
>   drivers/gpu/drm/i915/display/intel_lspcon.c       | 2 +-
>   include/drm/display/drm_dp_dual_mode_helper.h     | 2 +-
>   3 files changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> index 14a2a8473682..ae9d6b93136b 100644
> --- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> @@ -491,11 +491,10 @@ EXPORT_SYMBOL(drm_lspcon_get_mode);
>    * 0 on success, -error on failure/timeout
>    */
>   int drm_lspcon_set_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
> -			enum drm_lspcon_mode mode)
> +			enum drm_lspcon_mode mode, int time_out)

Add documentation for new argument 'time_out', as also reported by 
kernel test robot.

Otherwise looks good to me.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>

>   {
>   	u8 data = 0;
>   	int ret;
> -	int time_out = 200;
>   	enum drm_lspcon_mode current_mode;
>   
>   	if (mode == DRM_LSPCON_MODE_PCON)
> diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.c b/drivers/gpu/drm/i915/display/intel_lspcon.c
> index f9db867fae89..764cf4898364 100644
> --- a/drivers/gpu/drm/i915/display/intel_lspcon.c
> +++ b/drivers/gpu/drm/i915/display/intel_lspcon.c
> @@ -211,7 +211,7 @@ static int lspcon_change_mode(struct intel_lspcon *lspcon,
>   		return 0;
>   	}
>   
> -	err = drm_lspcon_set_mode(intel_dp->aux.drm_dev, ddc, mode);
> +	err = drm_lspcon_set_mode(intel_dp->aux.drm_dev, ddc, mode, lspcon_get_mode_settle_timeout(lspcon));
>   	if (err < 0) {
>   		drm_err(display->drm, "LSPCON mode change failed\n");
>   		return err;
> diff --git a/include/drm/display/drm_dp_dual_mode_helper.h b/include/drm/display/drm_dp_dual_mode_helper.h
> index 7ee482265087..7ac6969db935 100644
> --- a/include/drm/display/drm_dp_dual_mode_helper.h
> +++ b/include/drm/display/drm_dp_dual_mode_helper.h
> @@ -117,5 +117,5 @@ const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type);
>   int drm_lspcon_get_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
>   			enum drm_lspcon_mode *current_mode);
>   int drm_lspcon_set_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
> -			enum drm_lspcon_mode reqd_mode);
> +			enum drm_lspcon_mode reqd_mode, int time_out);
>   #endif
Re: [PATCH] drm/i915/lspcon: do not hardcode settle timeout
Posted by kernel test robot 1 year, 3 months ago 
Hi Giedrius,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.12-rc3 next-20241015]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Giedrius-Statkevi-ius/drm-i915-lspcon-do-not-hardcode-settle-timeout/20241014-174131
base:   linus/master
patch link:    https://lore.kernel.org/r/20241014093914.109162-1-giedriuswork%40gmail.com
patch subject: [PATCH] drm/i915/lspcon: do not hardcode settle timeout
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20241015/202410151813.Hw9oCTae-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241015/202410151813.Hw9oCTae-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410151813.Hw9oCTae-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:495: warning: Function parameter or struct member 'time_out' not described in 'drm_lspcon_set_mode'


vim +495 drivers/gpu/drm/display/drm_dp_dual_mode_helper.c

056996b9568632 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Shashank Sharma       2016-10-17  482  
056996b9568632 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Shashank Sharma       2016-10-17  483  /**
613a308159e5dd drivers/gpu/drm/drm_dp_dual_mode_helper.c         Jani Nikula           2016-10-19  484   * drm_lspcon_set_mode: Change LSPCON's mode of operation by
613a308159e5dd drivers/gpu/drm/drm_dp_dual_mode_helper.c         Jani Nikula           2016-10-19  485   * writing offset (0x80, 0x40)
318fbd7dfedd67 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Lyude Paul            2021-04-23  486   * @dev: &drm_device to use
613a308159e5dd drivers/gpu/drm/drm_dp_dual_mode_helper.c         Jani Nikula           2016-10-19  487   * @adapter: I2C-over-aux adapter
613a308159e5dd drivers/gpu/drm/drm_dp_dual_mode_helper.c         Jani Nikula           2016-10-19  488   * @mode: required mode of operation
056996b9568632 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Shashank Sharma       2016-10-17  489   *
056996b9568632 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Shashank Sharma       2016-10-17  490   * Returns:
056996b9568632 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Shashank Sharma       2016-10-17  491   * 0 on success, -error on failure/timeout
056996b9568632 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Shashank Sharma       2016-10-17  492   */
318fbd7dfedd67 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Lyude Paul            2021-04-23  493  int drm_lspcon_set_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
3d7a1094af9e7e drivers/gpu/drm/display/drm_dp_dual_mode_helper.c Giedrius Statkevičius 2024-10-14  494  			enum drm_lspcon_mode mode, int time_out)
056996b9568632 drivers/gpu/drm/drm_dp_dual_mode_helper.c         Shashank Sharma       2016-10-17 @495  {

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