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. 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 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox