From: Claudiu Beznea claudiu.beznea@microchip.com
[ 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 claudiu.beznea@microchip.com Link: https://lore.kernel.org/r/20221026124114.985876-2-claudiu.beznea@microchip.c... Signed-off-by: Sasha Levin sashal@kernel.org --- 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 ffed4d949042..e4904faf1753 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 6ce3bd22f6c6..5ad7ac2e3a7c 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 */