Re: [PATCH v2] arm64: dts: qcom: sc8280xp: correct ref_aux clock for ufs_mem_phy

[Bjorn Andersson]

On Thu, Aug 25, 2022 at 12:37:55PM -0400, Brian Masney wrote:
> The first UFS host controller fails to start on the SA8540P automotive
> board (QDrive3) due to the following errors:
> 
>     ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
>     ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
>     ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
>     ufshcd-qcom 1d84000.ufs: ufshcd_query_flag_retry: query attribute, opcode 5, idn 18, failed
>         with error 253 after 3 retries
> 
> The system eventually fails to boot with the warning:
> 
>     gcc_ufs_phy_axi_clk status stuck at 'off'
> 
> This issue can be worked around by adding clk_ignore_unused to the
> kernel command line since the system firmware sets up this clock for us.
> 
> Let's fix this issue by updating the ref_aux clock on ufs_mem_phy. Note
> that the downstream MSM 5.4 sources list this as ref_clk_parent. With
> this patch, the SA8540P is able to be booted without clk_ignore_unused.
> 
> Signed-off-by: Brian Masney <bmasney@xxxxxxxxxx>
> Fixes: 152d1faf1e2f3 ("arm64: dts: qcom: add SC8280XP platform")
> ---
> v1 of this patch can be found at
> https://lore.kernel.org/lkml/20220623142837.3140680-1-bmasney@xxxxxxxxxx/T/#u
> 
> Note that there's also a similar issue with the second UFS controller
> (ufs_card_hc) since it separately fails with:
> 
>     ufshcd-qcom 1da4000.ufs: Controller enable failed
>     ufshcd-qcom 1da4000.ufs: link startup failed 1
>     ...
>     gcc_ufs_card_axi_clk status stuck at 'off'
> 
> We are currently disabling the second UFS host controller (ufs_card_hc) in
> our DTS at the moment. I'm still looking through the downstream code to
> try to track this particular issue down.
> 
>  arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> index 49ea8b5612fc..4117ec0ffefc 100644
> --- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> @@ -892,7 +892,7 @@ ufs_mem_phy: phy@1d87000 {
>  			clock-names = "ref",
>  				      "ref_aux";
>  			clocks = <&rpmhcc RPMH_CXO_CLK>,
> -				 <&gcc GCC_UFS_PHY_PHY_AUX_CLK>;
> +				 <&gcc GCC_UFS_REF_CLKREF_CLK>;

I would expect that "ref" was going to be GCC_UFS_REF_CLKREF_CLK and
"ref_aux" would remain PHY_AUX. But the mapping here is not clear to me.

But does that work for you? (i.e. clocks = <CLKREF>, <PHY_AUX>)

Regards,
Bjorn

>  
>  			resets = <&ufs_mem_hc 0>;
>  			reset-names = "ufsphy";
> -- 
> 2.37.1
>