Re: [PATCH v1 1/3] ram: starfive: drop references to 16GB memory size

Heinrich Schuchardt
2025-10-30T07:53:36Z

On 10/30/25 07:23, E Shattow wrote:
> 16GB memory size is not addressable on StarFive JH-7110 SoC because the
> DRAM uncached alias begins at +8GB offset from start of DRAM. The logic
> for 16GB memory size is a fall-through to the default for an unknown size.
> Let's drop this unnecessary 16GB memory size and rely on the case default.
>
> Signed-off-by: E Shattow <e@freeshell.de>
> ---
> drivers/ram/starfive/ddrcsr_boot.c | 3 ---
> drivers/ram/starfive/ddrphy_start.c | 1 -
> drivers/ram/starfive/starfive_ddr.c | 1 -
> drivers/ram/starfive/starfive_ddr.h | 1 -
> 4 files changed, 6 deletions(-)
>
> diff --git a/drivers/ram/starfive/ddrcsr_boot.c b/drivers/ram/starfive/ddrcsr_boot.c
> index 6764b3ed5cc..ece6f5aae94 100644
> --- a/drivers/ram/starfive/ddrcsr_boot.c
> +++ b/drivers/ram/starfive/ddrcsr_boot.c
> @@ -231,7 +231,6 @@ void ddrcsr_boot(u32 *csrreg, u32 *secreg, u32 *phyreg, enum ddr_size_t size)
> mask = REG8G;
> break;
>
> - case DDR_SIZE_16G:
> default:
> return;
> };
> @@ -260,7 +259,6 @@ void ddrcsr_boot(u32 *csrreg, u32 *secreg, u32 *phyreg, enum ddr_size_t size)
> out_le32(csrreg + REGOFFSET(0x10), 0x3c);
> break;
>
> - case DDR_SIZE_16G:
> default:
> break;
> };
> @@ -286,7 +284,6 @@ void ddrcsr_boot(u32 *csrreg, u32 *secreg, u32 *phyreg, enum ddr_size_t size)
> break;
>
> case DDR_SIZE_2G:

Why don't we drop the line above? It is just falling through to default.

Best regards

Heinrich

> - case DDR_SIZE_16G:
> default:
> break;
> };
> diff --git a/drivers/ram/starfive/ddrphy_start.c b/drivers/ram/starfive/ddrphy_start.c
> index efe3f8a181a..f26bc9ccaad 100644
> --- a/drivers/ram/starfive/ddrphy_start.c
> +++ b/drivers/ram/starfive/ddrphy_start.c
> @@ -267,7 +267,6 @@ void ddr_phy_start(u32 *phyreg, enum ddr_size_t size)
> mask = REG8G;
> break;
>
> - case DDR_SIZE_16G:
> default:
> return;
> };
> diff --git a/drivers/ram/starfive/starfive_ddr.c b/drivers/ram/starfive/starfive_ddr.c
> index b31ed3bcf61..9e902f03ee9 100644
> --- a/drivers/ram/starfive/starfive_ddr.c
> +++ b/drivers/ram/starfive/starfive_ddr.c
> @@ -47,7 +47,6 @@ static int starfive_ddr_setup(struct udevice *dev, struct starfive_ddr_priv *pri
> size = DDR_SIZE_8G;
> break;
>
> - case 0x400000000:
> default:
> pr_err("unsupport size %lx\n", priv->info.size);
> return -EINVAL;
> diff --git a/drivers/ram/starfive/starfive_ddr.h b/drivers/ram/starfive/starfive_ddr.h
> index c29d26b510c..3ab0b0e8fa6 100644
> --- a/drivers/ram/starfive/starfive_ddr.h
> +++ b/drivers/ram/starfive/starfive_ddr.h
> @@ -48,7 +48,6 @@ enum ddr_size_t {
> DDR_SIZE_2G,
> DDR_SIZE_4G,
> DDR_SIZE_8G,
> - DDR_SIZE_16G,
> };
>
> void ddr_phy_train(u32 *phyreg);