Re: [PATCH v2 16/17] crypto: qce: Defer probe in case interconnect is not yet initialized

[Thara Gopinath <thara.gopinath@linaro.org>]

On 5/5/21 5:37 PM, Bhupesh Sharma wrote:
> On some Qualcomm parts the qce crypto driver needs the interconnect between
> the crypto block and main memory to be initialized first before the crypto
> registers can be accessed. So it makes sense to defer the qce crypto driver
> probing in case the interconnect driver is not yet probed.
> 
> This fixes the qce probe failure issues when both qce and
> interconnect drivers are compiled as static part of the kernel.
> 
> Cc: Thara Gopinath <thara.gopinath@linaro.org>
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Andy Gross <agross@kernel.org>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Stephen Boyd <sboyd@kernel.org>
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: dmaengine@vger.kernel.org
> Cc: linux-clk@vger.kernel.org
> Cc: linux-crypto@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: bhupesh.linux@gmail.com
> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
> ---
>   drivers/crypto/qce/core.c | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/crypto/qce/core.c b/drivers/crypto/qce/core.c
> index 3e742e9911fa..9915b184f780 100644
> --- a/drivers/crypto/qce/core.c
> +++ b/drivers/crypto/qce/core.c
> @@ -222,6 +222,20 @@ static int qce_crypto_probe(struct platform_device *pdev)
>   		return ret;
>   
>   	qce->mem_path = of_icc_get(qce->dev, "memory");
> +
> +	/* Check for NULL return path, which indicates
> +	 * interconnect API is disabled or the "interconnects"
> +	 * DT property is missing.
> +	 */
> +	if (!qce->mem_path)
> +		/* On some qcom parts, the qce crypto block needs interconnect
> +		 * paths to be configured before the registers can be accessed.
> +		 * Check here for the same.
> +		 */
> +		if (!strcmp(of_id->compatible, "qcom,ipq6018-qce") ||
> +		    !strcmp(of_id->compatible, "qcom,sdm845-qce"))
> +			return -EPROBE_DEFER;
> +

Hi Bhupesh,

You don't need this here. of_icc_get returns -EPROBE_DEFER if the 
interconnect provider is not initialized yet.

-- 
Warm Regards
Thara

>   	if (IS_ERR(qce->mem_path))
>   		return PTR_ERR(qce->mem_path);
>   
>