[PATCH u-boot v2019.04-aspeed-openbmc v2] ram/aspeed: Re-init ECC if requested but not enabled

[Adriana Kobylak]

> On Sep 21, 2022, at 2:46 AM, Joel Stanley <joel at jms.id.au> wrote:
> 
> If a machine has a new u-boot installed that enables ECC, but it has not
> had a power cycle since being updated, the DDR will not re-initalise and
> ECC will stay disabled.
> 
> Similarly for the reverse case, where ECC was enabled but a new u-boot
> disables it.
> 
> Detect if ECC has been requested by the firmware and check against the
> hardware state. If it does not match, and the DDR has already been
> initialised, proceed as if the DDR has not been set up.
> 
> Signed-off-by: Joel Stanley <joel at jms.id.au>

Reviewed-by: Adriana Kobylak <anoo at us.ibm.com>
Tested-by: Adriana Kobylak <anoo at us.ibm.com>

> ---
> v2:
> Add ast2500 too
> Fix logic for if (required) test
> ---
> drivers/ram/aspeed/sdram_ast2500.c | 23 ++++++++++++++++++++++-
> drivers/ram/aspeed/sdram_ast2600.c | 27 +++++++++++++++++++++++++--
> 2 files changed, 47 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/ram/aspeed/sdram_ast2500.c b/drivers/ram/aspeed/sdram_ast2500.c
> index c8eee32da698..f89dd78487e9 100644
> --- a/drivers/ram/aspeed/sdram_ast2500.c
> +++ b/drivers/ram/aspeed/sdram_ast2500.c
> @@ -409,6 +409,27 @@ static void ast2500_sdrammc_lock(struct dram_info *info)
> 		;
> }
> 
> +static bool ast2500_sdrammc_init_required(struct udevice *dev)
> +{
> +	struct dram_info *priv = dev_get_priv(dev);
> +	struct ast2500_sdrammc_regs *regs = priv->regs;
> +	bool ecc_requested;
> +	bool ecc_enabled;
> +	bool dram_ready;
> +
> +	ecc_requested = dev_read_bool(dev, "aspeed,ecc-enabled");
> +	ecc_enabled = readl(&regs->config) & SDRAM_CONF_ECC_EN;
> +	dram_ready  = readl(&priv->scu->vga_handshake[0]) & BIT(6);
> +
> +	if (!dram_ready)
> +		return true;
> +
> +	if (ecc_requested != ecc_enabled)
> +		return true;
> +
> +	return false;
> +}
> +
> static int ast2500_sdrammc_probe(struct udevice *dev)
> {
> 	struct dram_info *priv = (struct dram_info *)dev_get_priv(dev);
> @@ -437,7 +458,7 @@ static int ast2500_sdrammc_probe(struct udevice *dev)
> 		return PTR_ERR(priv->scu);
> 	}
> 
> -	if (readl(&priv->scu->vga_handshake[0]) & (0x1 << 6)) {
> +	if (!ast2500_sdrammc_init_required(dev)) {
> 		ast2500_sdrammc_update_size(priv);
> 
> 		if (!(readl(&priv->regs->config) & SDRAM_CONF_CACHE_EN)) {
> diff --git a/drivers/ram/aspeed/sdram_ast2600.c b/drivers/ram/aspeed/sdram_ast2600.c
> index 5f7b160faddf..66b5dd1fe6a9 100644
> --- a/drivers/ram/aspeed/sdram_ast2600.c
> +++ b/drivers/ram/aspeed/sdram_ast2600.c
> @@ -891,6 +891,30 @@ static void ast2600_sdrammc_ecc_enable(struct dram_info *info, u32 conf_size_mb)
> 	writel(0, &regs->intr_ctrl);
> }
> 
> +static bool ast2600_sdrammc_init_required(struct udevice *dev)
> +{
> +	struct dram_info *priv = dev_get_priv(dev);
> +	struct ast2600_sdrammc_regs *regs = priv->regs;
> +	bool ecc_requested;
> +	bool ecc_enabled;
> +	bool dram_ready;
> +
> +	ecc_requested = dev_read_bool(dev, "aspeed,ecc-enabled");
> +	ecc_enabled = readl(&regs->config) & SDRAM_CONF_ECC_SETUP;
> +	dram_ready  = readl(priv->scu + AST_SCU_HANDSHAKE) & SCU_SDRAM_INIT_READY_MASK;
> +
> +	debug("ECC: requested %d enabled %d dram ready %d\n",
> +			ecc_requested, ecc_enabled, dram_ready);
> +
> +	if (!dram_ready)
> +		return true;
> +
> +	if (ecc_requested != ecc_enabled)
> +		return true;
> +
> +	return false;
> +}
> +
> static int ast2600_sdrammc_probe(struct udevice *dev)
> {
> 	struct dram_info *priv = (struct dram_info *)dev_get_priv(dev);
> @@ -913,8 +937,7 @@ static int ast2600_sdrammc_probe(struct udevice *dev)
> 		return PTR_ERR(priv->scu);
> 	}
> 
> -	reg = readl(priv->scu + AST_SCU_HANDSHAKE);
> -	if (reg & SCU_SDRAM_INIT_READY_MASK) {
> +	if (!ast2600_sdrammc_init_required(dev)) {
> 		printf("already initialized, ");
> 		setbits_le32(priv->scu + AST_SCU_HANDSHAKE, SCU_HANDSHAKE_MASK);
> 		ast2600_sdrammc_update_size(priv);
> -- 
> 2.35.1
>