linux-kernel - [PATCH v4 1/7] memory: tegra: Remove periodic compensation duplicate calls

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Message-Id: <20240704-tegra210_emcfreq-v4-1-3e450503c555@tecnico.ulisboa.pt>
Date: Thu, 04 Jul 2024 12:31:20 +0100
From: Diogo Ivo <diogo.ivo@...nico.ulisboa.pt>
To: Krzysztof Kozlowski <krzk@...nel.org>, 
 Thierry Reding <thierry.reding@...il.com>, 
 Jonathan Hunter <jonathanh@...dia.com>
Cc: linux-kernel@...r.kernel.org, linux-tegra@...r.kernel.org, 
 Diogo Ivo <diogo.ivo@...nico.ulisboa.pt>
Subject: [PATCH v4 1/7] memory: tegra: Remove periodic compensation
 duplicate calls

Prior to calling periodic_compensation_handler() the code is doing one
extra DRAM delay reading which is unnecessary as this is already done
in periodic_compensation_handler(), so remove these extra calls.

Signed-off-by: Diogo Ivo <diogo.ivo@...nico.ulisboa.pt>
---
 drivers/memory/tegra/tegra210-emc-cc-r21021.c | 19 ++-----------------
 1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/drivers/memory/tegra/tegra210-emc-cc-r21021.c b/drivers/memory/tegra/tegra210-emc-cc-r21021.c
index 4cb608c71ead..9ec49ced8f91 100644
--- a/drivers/memory/tegra/tegra210-emc-cc-r21021.c
+++ b/drivers/memory/tegra/tegra210-emc-cc-r21021.c
@@ -492,7 +492,6 @@ static u32 tegra210_emc_r21021_periodic_compensation(struct tegra210_emc *emc)
 	};
 	struct tegra210_emc_timing *last = emc->last;
 	unsigned int items = ARRAY_SIZE(list), i;
-	unsigned long delay;
 
 	if (last->periodic_training) {
 		emc_dbg(emc, PER_TRAIN, "Periodic training starting\n");
@@ -530,18 +529,9 @@ static u32 tegra210_emc_r21021_periodic_compensation(struct tegra210_emc *emc)
 		/*
 		 * 2. osc kick off - this assumes training and dvfs have set
 		 *    correct MR23.
-		 */
-		tegra210_emc_start_periodic_compensation(emc);
-
-		/*
+		 *
 		 * 3. Let dram capture its clock tree delays.
-		 */
-		delay = tegra210_emc_actual_osc_clocks(last->run_clocks);
-		delay *= 1000;
-		delay /= last->rate + 1;
-		udelay(delay);
-
-		/*
+		 *
 		 * 4. Check delta wrt previous values (save value if margin
 		 *    exceeds what is set in table).
 		 */
@@ -734,11 +724,6 @@ static void tegra210_emc_r21021_set_clock(struct tegra210_emc *emc, u32 clksrc)
 						     EMC_EMC_STATUS_DRAM_IN_SELF_REFRESH_MASK,
 						     0);
 
-		tegra210_emc_start_periodic_compensation(emc);
-
-		delay = 1000 * tegra210_emc_actual_osc_clocks(last->run_clocks);
-		udelay((delay / last->rate) + 2);
-
 		value = periodic_compensation_handler(emc, DVFS_SEQUENCE, fake,
 						      next);
 		value = (value * 128 * next->rate / 1000) / 1000000;

-- 
2.45.2