From 2aee616a6b1104ce3bf7db0ec37bb33c739a1062 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Wed, 26 Oct 2022 15:41:04 +0300 Subject: [PATCH] ARM: at91: pm: avoid soft resetting AC DLL [ Upstream commit cef8cdc0d0e7c701fe4dcfba4ed3fd25d28a6020 ] Do not soft reset AC DLL as controller is buggy and this operation my introduce glitches in the controller leading to undefined behavior. Fixes: f0bbf17958e8 ("ARM: at91: pm: add self-refresh support for sama7g5") Depends-on: a02875c4cbd6 ("ARM: at91: pm: fix self-refresh for sama7g5") Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20221026124114.985876-2-claudiu.beznea@microchip.com Signed-off-by: Sasha Levin --- arch/arm/mach-at91/pm_suspend.S | 7 ++++++- include/soc/at91/sama7-ddr.h | 5 ++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S index 65cfcc1..2f0a370 100644 --- a/arch/arm/mach-at91/pm_suspend.S +++ b/arch/arm/mach-at91/pm_suspend.S @@ -169,10 +169,15 @@ sr_ena_2: cmp tmp1, #UDDRC_STAT_SELFREF_TYPE_SW bne sr_ena_2 - /* Put DDR PHY's DLL in bypass mode for non-backup modes. */ + /* Disable DX DLLs for non-backup modes. */ cmp r7, #AT91_PM_BACKUP beq sr_ena_3 + /* Do not soft reset the AC DLL. */ + ldr tmp1, [r3, DDR3PHY_ACDLLCR] + bic tmp1, tmp1, DDR3PHY_ACDLLCR_DLLSRST + str tmp1, [r3, DDR3PHY_ACDLLCR] + /* Disable DX DLLs. */ ldr tmp1, [r3, #DDR3PHY_DX0DLLCR] orr tmp1, tmp1, #DDR3PHY_DXDLLCR_DLLDIS diff --git a/include/soc/at91/sama7-ddr.h b/include/soc/at91/sama7-ddr.h index f203f34..cac3f9c 100644 --- a/include/soc/at91/sama7-ddr.h +++ b/include/soc/at91/sama7-ddr.h @@ -26,7 +26,10 @@ #define DDR3PHY_PGSR (0x0C) /* DDR3PHY PHY General Status Register */ #define DDR3PHY_PGSR_IDONE (1 << 0) /* Initialization Done */ -#define DDR3PHY_ACIOCR (0x24) /* DDR3PHY AC I/O Configuration Register */ +#define DDR3PHY_ACDLLCR (0x14) /* DDR3PHY AC DLL Control Register */ +#define DDR3PHY_ACDLLCR_DLLSRST (1 << 30) /* DLL Soft Reset */ + +#define DDR3PHY_ACIOCR (0x24) /* DDR3PHY AC I/O Configuration Register */ #define DDR3PHY_ACIOCR_CSPDD_CS0 (1 << 18) /* CS#[0] Power Down Driver */ #define DDR3PHY_ACIOCR_CKPDD_CK0 (1 << 8) /* CK[0] Power Down Driver */ #define DDR3PHY_ACIORC_ACPDD (1 << 3) /* AC Power Down Driver */ -- 2.7.4