Hi, On 28.10.21 15:06, Joacim Zetterling wrote: > On Thu, Oct 28, 2021 at 02:19:18PM +0200, Ahmad Fatoum wrote: >> Hello Joacim, >> >> On 28.10.21 10:46, Joacim Zetterling wrote: >>> The imx8mn has a 16-bit SDRAM bus width access but the calculation >>> of the memory size treat it as a 32-bit width bus which makes the >>> memory calculation to be wrong (meminfo wrong and memtest fails). >> >> I missed this because of the /memory node in the device tree filling >> up the remainder. I removed /memory and tried your patch on an >> i.MX8MN DDR EVK, but it doesn't change iomem output: >> >> 0x0000000040000000 - 0x000000007fffffff (size 0x0000000040000000) ram0 >> >> The 8MN DDR4 EVK reports FIELD_GET(DDRC_MSTR_DEVICE_CONFIG, mstr) == 0b10 >> and FIELD_GET(DDRC_MSTR_DATA_BUS_WIDTH, mstr) == 0b00. >> >>> There is a difference between the imx7 and the imx8 familys. >>> The imx8 family has a device config field in the master register of >>> the DDRC controller which the imx7 family doesn't have (the bus width >>> is 32-bit as default). >>> >>> The device config field together with the DQ configuration tells us >>> the actual bus width of the device for a correct mem size calculaton. >>> >>> From the imx8mn reference manual: >>> +----------------------------------------------------+ >>> | Field | Function | >>> |----------------------------------------------------| >>> | 31-30 | Indicates the configuration of the | >>> | | device used in the system. | >>> | device_config | 00b - x4 device | >>> | | 01b - x8 device | >>> | | 10b - x16 device | >>> | | 11b - x32 device | >>> +----------------------------------------------------+ >>> ... >>> ... >>> >>> Tested on the IMX8MN Evk with 2GB DDR4 and on a IMX8MN custom board >>> with 2GB LPDDR4, checked size and made memory test. >> >> What's the device_config for each? > The device_config for both platforms are b10 > >> >>> Signed-off-by: Joacim Zetterling <joacim.zetterling@xxxxxxxxxxxx> >>> --- >>> arch/arm/mach-imx/esdctl.c | 16 +++++++++++----- >>> 1 file changed, 11 insertions(+), 5 deletions(-) >>> >>> diff --git a/arch/arm/mach-imx/esdctl.c b/arch/arm/mach-imx/esdctl.c >>> index e56da3cb76d4..f80d94f2fca0 100644 >>> --- a/arch/arm/mach-imx/esdctl.c >>> +++ b/arch/arm/mach-imx/esdctl.c >>> @@ -320,6 +320,7 @@ static int vf610_ddrmc_add_mem(void *mmdcbase, struct imx_esdctl_data *data) >>> #define DDRC_MSTR_LPDDR4 BIT(5) >>> #define DDRC_MSTR_DATA_BUS_WIDTH GENMASK(13, 12) >>> #define DDRC_MSTR_ACTIVE_RANKS GENMASK(27, 24) >>> +#define DDRC_MSTR_DEVICE_CONFIG GENMASK(31, 30) >>> >>> #define DDRC_ADDRMAP0_CS_BIT1 GENMASK(12, 8) >>> >>> @@ -361,7 +362,7 @@ static resource_size_t >>> imx_ddrc_sdram_size(void __iomem *ddrc, const u32 addrmap[], >>> u8 col_max, const u8 col_b[], unsigned int col_b_num, >>> u8 row_max, const u8 row_b[], unsigned int row_b_num, >>> - bool reduced_adress_space) >>> + bool reduced_adress_space, bool is_imx8) >>> { >>> const u32 mstr = readl(ddrc + DDRC_MSTR); >>> unsigned int banks, ranks, columns, rows, active_ranks, width; >>> @@ -384,15 +385,20 @@ imx_ddrc_sdram_size(void __iomem *ddrc, const u32 addrmap[], >>> BUG(); >>> } >>> >>> + if (is_imx8) >>> + width = (1 << FIELD_GET(DDRC_MSTR_DEVICE_CONFIG, mstr)) >> 1; >> >> for device_config == 0, size should be halved, but instead you would get a >> width of zero here. > Good catch! Need to treat bus width 4 in a special way when calculating > the memory size. i.e. > > if (width) > size = memory_sdram_size(columns, rows, 1 << banks, width); > else > size = memory_sdram_size(columns, rows, 1 << banks, 1) >> 1; > size <<= ranks; > >> >>> + else >>> + width = 4; >>> + >>> switch (FIELD_GET(DDRC_MSTR_DATA_BUS_WIDTH, mstr)) { >>> case 0b00: /* Full DQ bus */ >>> width = 4; >> >> I can't really follow. Shouldn't this be dropped to take the >> value of width above? > My bad! Should have been removed earlier. Now I wonder, how could v1 of this patch have worked for you? You should've had double the really existing RAM or am I missing something? > > switch (FIELD_GET(DDRC_MSTR_DATA_BUS_WIDTH, mstr)) { > case 0b00: /* Full DQ bus */ > break; > case 0b01: /* Half DQ bus */ > ... > ... >> >>> break; >>> case 0b01: /* Half DQ bus */ >>> - width = 2; >>> + width >>= 1; >>> break; >>> case 0b10: /* Quarter DQ bus */ >>> - width = 1; >>> + width >>= 2; >>> break; >>> default: >>> BUG(); >>> @@ -466,7 +472,7 @@ static resource_size_t imx8m_ddrc_sdram_size(void __iomem *ddrc) >>> return imx_ddrc_sdram_size(ddrc, addrmap, >>> 12, ARRAY_AND_SIZE(col_b), >>> 16, ARRAY_AND_SIZE(row_b), >>> - reduced_adress_space); >>> + reduced_adress_space, true); >>> } >>> >>> static int imx8m_ddrc_add_mem(void *mmdcbase, struct imx_esdctl_data *data) >>> @@ -508,7 +514,7 @@ static resource_size_t imx7d_ddrc_sdram_size(void __iomem *ddrc) >>> return imx_ddrc_sdram_size(ddrc, addrmap, >>> 11, ARRAY_AND_SIZE(col_b), >>> 15, ARRAY_AND_SIZE(row_b), >>> - reduced_adress_space); >>> + reduced_adress_space, false); >>> } >>> >>> static int imx7d_ddrc_add_mem(void *mmdcbase, struct imx_esdctl_data *data) >>> >> >> > I'll send a new patch version. >> -- >> Pengutronix e.K. | | >> Steuerwalder Str. 21 | https://urldefense.com/v3/__http://www.pengutronix.de/__;!!I9LPvj3b!UEEry3YzdrJRIMGgQgDd_crPHhM_0abIlHJq7-FIV6hTs9m7uhtHdAcHsA99yIw$ | >> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | >> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox