Re: [PATCH v2 15/17] crypto: qce: Defer probing if BAM dma is not yet initialized

[Thara Gopinath]

On 5/5/21 5:37 PM, Bhupesh Sharma wrote:
> Since the Qualcomm qce crypto driver needs the BAM dma driver to be
> setup first (to allow crypto operations), it makes sense to defer
> the qce crypto driver probing in case the BAM dma driver is not yet
> probed.
>
> This fixes the qce probe failure issues when both qce and BMA dma
> are compiled as static part of the kernel.
>
> Cc: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Andy Gross <agross@xxxxxxxxxx>
> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> Cc: Stephen Boyd <sboyd@xxxxxxxxxx>
> Cc: Michael Turquette <mturquette@xxxxxxxxxxxx>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Cc: dmaengine@xxxxxxxxxxxxxxx
> Cc: linux-clk@xxxxxxxxxxxxxxx
> Cc: linux-crypto@xxxxxxxxxxxxxxx
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: bhupesh.linux@xxxxxxxxx
> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxxxxxx>
> ---
>   drivers/crypto/qce/core.c  | 4 ++++
>   drivers/dma/qcom/bam_dma.c | 7 +++++++
>   2 files changed, 11 insertions(+)
>
> diff --git a/drivers/crypto/qce/core.c b/drivers/crypto/qce/core.c
> index 9a7d7ef94687..3e742e9911fa 100644
> --- a/drivers/crypto/qce/core.c
> +++ b/drivers/crypto/qce/core.c
> @@ -15,6 +15,7 @@
>   #include <linux/types.h>
>   #include <crypto/algapi.h>
>   #include <crypto/internal/hash.h>
> +#include <soc/qcom/bam_dma.h>
>   
>   #include "core.h"
>   #include "cipher.h"
> @@ -201,6 +202,9 @@ static int qce_crypto_probe(struct platform_device *pdev)
>   			of_match_device(qce_crypto_of_match, &pdev->dev);
>   	int ret;
>   
> +	/* qce driver requires BAM dma driver to be setup first */
> +	if (!bam_is_probed())
> +		return -EPROBE_DEFER;

Hi Bhupesh,

You don't need this here. qce_dma_request returns -EPROBE_DEFER if the 
dma controller is not probed yet.

--
Warm Regards
Thara
>   
>   	qce = devm_kzalloc(dev, sizeof(*qce), GFP_KERNEL);
>   	if (!qce)
> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
> index 2bc3b7c7ee5a..c854fcc82dbf 100644
> --- a/drivers/dma/qcom/bam_dma.c
> +++ b/drivers/dma/qcom/bam_dma.c
> @@ -935,6 +935,12 @@ static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
>   	INIT_LIST_HEAD(&bchan->desc_list);
>   }
>   
> +bool bam_is_probed(void)
> +{
> +	return bam_probed;
> +}
> +EXPORT_SYMBOL_GPL(bam_is_probed);
> +
>   static const struct of_device_id bam_of_match[] = {
>   	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
>   	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
> @@ -1084,6 +1090,7 @@ static int bam_dma_probe(struct platform_device *pdev)
>   	if (ret)
>   		goto err_unregister_dma;
>   
> +	bam_probed = true;
>   	if (!bdev->bamclk) {
>   		pm_runtime_disable(&pdev->dev);
>   		return 0;