u-boot/board/tq/tqma6/tqma6q.cfg
Miquel Raynal 49a3e0b9e2 tqma6: Fix DDR configuration
Initially investigating a Linux network issue causing a lot of drop and
poor network performances on a custom system based on a TQMA6A module
(based on an iMX6Q), [1st link below].

I eventually correlated my observations with a contention at the NIC
level when in concurrency with the graphics pipeline. Troubleshooting
this in the kernel lead to disabling DMA bursts accesses made by the IPU
in order to avoid triggering the QoS at the interconnect level, reducing
from 50 to 10% the drop rate on eth0, [2nd link below]. The solution
worked on my setup but not on others, which still suffered from
abnormally high drop rates even with this "fix".

After looking a while into TQ Systems BSP I figured out a number of
differences in recent U-Boot out-of-tree patches they had in their
repository [3rd link]. Parsing the differences one after the other lead
me to this final solution.

The reset pad of the DDR controller was apparently misconfigured, Bit
18-19 picturing the "DDR select field". The current value b11 is
reserved. The only defined value as of version 6 of the iMX6Q manual was
b00 "DDR3 and LPDDR2 mode". In practice no register difference has been
spotted after changing this configuration but all issues tracked thus
far just vanished. All previous fixes have been proven irrelevant. Just
clearing this field solved all our network issues and the drop rate as
measured by iperf3 felt back to 0%.

Link: https://lore.kernel.org/netdev/20231012193410.3d1812cf@xps-13/
Link: https://lists.freedesktop.org/archives/dri-devel/2023-October/428251.html
Link: 15eb6abbef
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
2023-12-12 16:33:57 -05:00

123 lines
4.1 KiB
INI

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2013, 2014 Markus Niebel <Markus.Niebel@tq-group.com>
*
* Refer doc/imx/mkimage/imximage.txt for more details about how-to configure
* and create imximage boot image
*
* The syntax is taken as close as possible with the kwbimage
*/
/* image version */
IMAGE_VERSION 2
#include <config.h>
/*
* Boot Device : one of
* spi, sd (the board has no nand neither onenand)
*/
#if defined(CONFIG_TQMA6X_MMC_BOOT)
BOOT_FROM sd
#elif defined(CONFIG_TQMA6X_SPI_BOOT)
BOOT_FROM spi
#endif
#include "asm/arch/mx6-ddr.h"
#include "asm/arch/iomux.h"
#include "asm/arch/crm_regs.h"
/* TQMa6Q/D DDR config Rev. 0100B */
/* IOMUX configuration */
DATA 4, MX6_IOM_GRP_DDR_TYPE, 0x000C0000
DATA 4, MX6_IOM_GRP_DDRPKE, 0x00000000
DATA 4, MX6_IOM_DRAM_SDCLK_0, 0x00008030
DATA 4, MX6_IOM_DRAM_SDCLK_1, 0x00008030
DATA 4, MX6_IOM_DRAM_CAS, 0x00008030
DATA 4, MX6_IOM_DRAM_RAS, 0x00008030
DATA 4, MX6_IOM_GRP_ADDDS, 0x00000030
DATA 4, MX6_IOM_DRAM_RESET, 0x00003030
DATA 4, MX6_IOM_DRAM_SDCKE0, 0x00003000
DATA 4, MX6_IOM_DRAM_SDCKE1, 0x00000000
DATA 4, MX6_IOM_DRAM_SDBA2, 0x00000000
DATA 4, MX6_IOM_DRAM_SDODT0, 0x00003030
DATA 4, MX6_IOM_DRAM_SDODT1, 0x00003030
DATA 4, MX6_IOM_GRP_CTLDS, 0x00000030
DATA 4, MX6_IOM_DDRMODE_CTL, 0x00020000
DATA 4, MX6_IOM_DRAM_SDQS0, 0x00000030
DATA 4, MX6_IOM_DRAM_SDQS1, 0x00000030
DATA 4, MX6_IOM_DRAM_SDQS2, 0x00000030
DATA 4, MX6_IOM_DRAM_SDQS3, 0x00000030
DATA 4, MX6_IOM_DRAM_SDQS4, 0x00000030
DATA 4, MX6_IOM_DRAM_SDQS5, 0x00000030
DATA 4, MX6_IOM_DRAM_SDQS6, 0x00000030
DATA 4, MX6_IOM_DRAM_SDQS7, 0x00000030
DATA 4, MX6_IOM_GRP_DDRMODE, 0x00020000
DATA 4, MX6_IOM_GRP_B0DS, 0x00000030
DATA 4, MX6_IOM_GRP_B1DS, 0x00000030
DATA 4, MX6_IOM_GRP_B2DS, 0x00000030
DATA 4, MX6_IOM_GRP_B3DS, 0x00000030
DATA 4, MX6_IOM_GRP_B4DS, 0x00000030
DATA 4, MX6_IOM_GRP_B5DS, 0x00000030
DATA 4, MX6_IOM_GRP_B6DS, 0x00000030
DATA 4, MX6_IOM_GRP_B7DS, 0x00000030
DATA 4, MX6_IOM_DRAM_DQM0, 0x00000030
DATA 4, MX6_IOM_DRAM_DQM1, 0x00000030
DATA 4, MX6_IOM_DRAM_DQM2, 0x00000030
DATA 4, MX6_IOM_DRAM_DQM3, 0x00000030
DATA 4, MX6_IOM_DRAM_DQM4, 0x00000030
DATA 4, MX6_IOM_DRAM_DQM5, 0x00000030
DATA 4, MX6_IOM_DRAM_DQM6, 0x00000030
DATA 4, MX6_IOM_DRAM_DQM7, 0x00000030
/* memory interface calibration values */
DATA 4, MX6_MMDC_P0_MPZQHWCTRL, 0xA1390003
DATA 4, MX6_MMDC_P1_MPZQHWCTRL, 0xA1390003
DATA 4, MX6_MMDC_P0_MPWLDECTRL0, 0x001B0013
DATA 4, MX6_MMDC_P0_MPWLDECTRL1, 0x0018001B
DATA 4, MX6_MMDC_P1_MPWLDECTRL0, 0x001B0016
DATA 4, MX6_MMDC_P1_MPWLDECTRL1, 0x0012001C
DATA 4, MX6_MMDC_P0_MPDGCTRL0, 0x43400350
DATA 4, MX6_MMDC_P0_MPDGCTRL1, 0x023E032C
DATA 4, MX6_MMDC_P1_MPDGCTRL0, 0x43400348
DATA 4, MX6_MMDC_P1_MPDGCTRL1, 0x03300304
DATA 4, MX6_MMDC_P0_MPRDDLCTL, 0x3C323436
DATA 4, MX6_MMDC_P1_MPRDDLCTL, 0x38383242
DATA 4, MX6_MMDC_P0_MPWRDLCTL, 0x3E3C4440
DATA 4, MX6_MMDC_P1_MPWRDLCTL, 0x4236483E
DATA 4, MX6_MMDC_P0_MPRDDQBY0DL, 0x33333333
DATA 4, MX6_MMDC_P0_MPRDDQBY1DL, 0x33333333
DATA 4, MX6_MMDC_P0_MPRDDQBY2DL, 0x33333333
DATA 4, MX6_MMDC_P0_MPRDDQBY3DL, 0x33333333
DATA 4, MX6_MMDC_P1_MPRDDQBY0DL, 0x33333333
DATA 4, MX6_MMDC_P1_MPRDDQBY1DL, 0x33333333
DATA 4, MX6_MMDC_P1_MPRDDQBY2DL, 0x33333333
DATA 4, MX6_MMDC_P1_MPRDDQBY3DL, 0x33333333
DATA 4, MX6_MMDC_P0_MPMUR0, 0x00000800
DATA 4, MX6_MMDC_P1_MPMUR0, 0x00000800
/* configure memory interface */
DATA 4, MX6_MMDC_P0_MDPDC, 0x00020036
DATA 4, MX6_MMDC_P0_MDOTC, 0x09444040
DATA 4, MX6_MMDC_P0_MDCFG0, 0x545A79B4
DATA 4, MX6_MMDC_P0_MDCFG1, 0xDB538F64
DATA 4, MX6_MMDC_P0_MDCFG2, 0x01FF00DB
DATA 4, MX6_MMDC_P0_MDMISC, 0x00001740
DATA 4, MX6_MMDC_P0_MDSCR, 0x00008000
DATA 4, MX6_MMDC_P0_MDRWD, 0x000026D2
DATA 4, MX6_MMDC_P0_MDOR, 0x005A1023
DATA 4, MX6_MMDC_P0_MDASP, 0x00000027
DATA 4, MX6_MMDC_P0_MDCTL, 0x831A0000
DATA 4, MX6_MMDC_P0_MDSCR, 0x00088032
DATA 4, MX6_MMDC_P0_MDSCR, 0x00008033
DATA 4, MX6_MMDC_P0_MDSCR, 0x00048031
DATA 4, MX6_MMDC_P0_MDSCR, 0x09308030
DATA 4, MX6_MMDC_P0_MDSCR, 0x04008040
DATA 4, MX6_MMDC_P0_MDREF, 0x00005800
DATA 4, MX6_MMDC_P0_MPODTCTRL, 0x00022222
DATA 4, MX6_MMDC_P1_MPODTCTRL, 0x00022222
DATA 4, MX6_MMDC_P0_MDPDC, 0x00025536
DATA 4, MX6_MMDC_P0_MAPSR, 0x00001006
DATA 4, MX6_MMDC_P0_MDSCR, 0x00000000
#include "clocks.cfg"