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ARM: at91: pm: avoid soft resetting AC DLL 

[ Upstream commit cef8cdc0d0 ]

Do not soft reset AC DLL as controller is buggy and this operation my
introduce glitches in the controller leading to undefined behavior.

Fixes: f0bbf17958 ("ARM: at91: pm: add self-refresh support for sama7g5")
Depends-on: a02875c4cb ("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.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Claudiu Beznea 2022-10-26 15:41:04 +03:00 committed by Greg Kroah-Hartman
parent e183378ddd
commit fff8890cba
2 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/arm/mach-at91/pm_suspend.S
View File

@ -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

5
include/soc/at91/sama7-ddr.h
View File

@ -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 */