[PATCH 0/2] memory: tegra: Fix DLL setting in EMC sequences

[PATCH 0/2] memory: tegra: Fix DLL setting in EMC sequences

[Mikko Perttunen]

The code related to DLL setting change is incorrect in the Tegra30/
Tegra124 EMC sequences -- fix them.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
Mikko Perttunen (2):
      memory: tegra124-emc: Fix dll_change check
      memory: tegra30-emc: Fix dll_change check

 drivers/memory/tegra/tegra124-emc.c | 2 +-
 drivers/memory/tegra/tegra30-emc.c  | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)
---
base-commit: a0c666c25aeefd16f4b088c6549a6fb6b65a8a1d
change-id: 20251126-fix-emc-dllchange-c2ff94dc7980

[PATCH 1/2] memory: tegra124-emc: Fix dll_change check

[Mikko Perttunen]

The code checking whether the specified memory timing enables DLL
in the EMRS register was reversed. DLL is enabled if bit A0 is low.
Fix the check.

Fixes: 73a7f0a90641 ("memory: tegra: Add EMC (external memory controller) driver")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
 drivers/memory/tegra/tegra124-emc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
index 9978ff911c47..05d0d8527961 100644
--- a/drivers/memory/tegra/tegra124-emc.c
+++ b/drivers/memory/tegra/tegra124-emc.c
@@ -608,7 +608,7 @@ static int tegra124_emc_prepare_timing_change(struct tegra_emc *emc,
 
 	if ((last->emc_mode_1 & 0x1) == (timing->emc_mode_1 & 0x1))
 		dll_change = DLL_CHANGE_NONE;
-	else if (timing->emc_mode_1 & 0x1)
+	else if (!(timing->emc_mode_1 & 0x1))
 		dll_change = DLL_CHANGE_ON;
 	else
 		dll_change = DLL_CHANGE_OFF;

-- 
2.52.0

[PATCH 2/2] memory: tegra30-emc: Fix dll_change check

[Mikko Perttunen]

The code checking whether the specified memory timing enables DLL
in the EMRS register was reversed. DLL is enabled if bit A0 is low.
Fix the check.

Fixes: e34212c75a68 ("memory: tegra: Introduce Tegra30 EMC driver")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
 drivers/memory/tegra/tegra30-emc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index 914116d8ec16..2c32d28156e0 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -554,14 +554,14 @@ static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate)
 	emc->emc_cfg = readl_relaxed(emc->regs + EMC_CFG);
 	emc_dbg = readl_relaxed(emc->regs + EMC_DBG);
 
-	if (emc->dll_on == !!(timing->emc_mode_1 & 0x1))
+	if (emc->dll_on == !(timing->emc_mode_1 & 0x1))
 		dll_change = DLL_CHANGE_NONE;
-	else if (timing->emc_mode_1 & 0x1)
+	else if (!(timing->emc_mode_1 & 0x1))
 		dll_change = DLL_CHANGE_ON;
 	else
 		dll_change = DLL_CHANGE_OFF;
 
-	emc->dll_on = !!(timing->emc_mode_1 & 0x1);
+	emc->dll_on = !(timing->emc_mode_1 & 0x1);
 
 	if (timing->data[80] && !readl_relaxed(emc->regs + EMC_ZCAL_INTERVAL))
 		emc->zcal_long = true;

-- 
2.52.0

Re: [PATCH 0/2] memory: tegra: Fix DLL setting in EMC sequences

[Krzysztof Kozlowski]

On Mon, 26 Jan 2026 15:50:41 +0900, Mikko Perttunen wrote:
> The code related to DLL setting change is incorrect in the Tegra30/
> Tegra124 EMC sequences -- fix them.
> 
> 

Applied, thanks!

[1/2] memory: tegra124-emc: Fix dll_change check
      https://git.kernel.org/krzk/linux-mem-ctrl/c/53f3329cd35797056ab915e8bc1c723ec38e2907
[2/2] memory: tegra30-emc: Fix dll_change check
      https://git.kernel.org/krzk/linux-mem-ctrl/c/3c6133ece23b5c3f90fe90c9e524bc322c52c921

Best regards,
-- 
Krzysztof Kozlowski <krzk@kernel.org>