| Message ID | 20221020023321.476550-2-paul.liu@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | imx8m: ddr_init: fix reading of DDR4 MR registers | expand |
Hi Paul, On 19/10/2022 23:33, Ying-Chun Liu (PaulLiu) wrote: > Accorting to commit 290ffe57886271a6 we need to read more significant > bytes to get a non-zero value. However commit 7e9bd84883aeb1e2 removes > it by accident. Thus we add the changes back. This is needed to let > imx8mm-cl-iot-gate to boot correctly. > > Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org> Rasmus has already submitted a fix for this: https://lore.kernel.org/u-boot/f623aec6ff75744183ce86d0a6e17a14@denx.de/T/#t Thanks
diff --git a/drivers/ddr/imx/imx8m/ddr_init.c b/drivers/ddr/imx/imx8m/ddr_init.c index d964184ddc..7a683b1d36 100644 --- a/drivers/ddr/imx/imx8m/ddr_init.c +++ b/drivers/ddr/imx/imx8m/ddr_init.c @@ -134,8 +134,14 @@ unsigned int lpddr4_mr_read(unsigned int mr_rank, unsigned int mr_addr) tmp = reg32_read(DRC_PERF_MON_MRR0_DAT(0)); } while ((tmp & 0x8) == 0); tmp = reg32_read(DRC_PERF_MON_MRR1_DAT(0)); - tmp = tmp & 0xff; reg32_write(DRC_PERF_MON_MRR0_DAT(0), 0x4); + while (tmp) { // try to find a significant byte in the word + if (tmp & 0xff) { + tmp &= 0xff; + break; + } + tmp >>= 8; + } return tmp; }
Accorting to commit 290ffe57886271a6 we need to read more significant bytes to get a non-zero value. However commit 7e9bd84883aeb1e2 removes it by accident. Thus we add the changes back. This is needed to let imx8mm-cl-iot-gate to boot correctly. Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org> Cc: Fabio Estevam <festevam@denx.de> Cc: Marek Vasut <marex@denx.de> Cc: Peng Fan <peng.fan@nxp.com> Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Cc: Stefano Babic <sbabic@denx.de> Cc: NXP i.MX U-Boot Team <uboot-imx@nxp.com> --- drivers/ddr/imx/imx8m/ddr_init.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)