[PATCH 3/3] coresight etm4x: Add pr_debug statement for Coresight component PID/CID

[Suzuki K Poulose]

Cc: Russell

nit: Subject line doesn't match the patch. This could be :

  "amba: bus: Add pr_debug for AMBA PID/CID"

On 20/01/2023 00:51, Steve Clevenger wrote:
> Add pr_debug statement to provide visibility into Coresight component PID
> and CID settings. This helped debug an intermittent clock related issue
> resulting in bad PID/CID values.

And this change belongs to the AMBA subsystem. Please run :

scripts/get_maintainer.pl on your patch and add the necessary people 
from that list for your patch.

As such, I don't think brings any value to be added to the tree.
I will leave it for the maintainers to comment.

Suzuki

> 
> Signed-off-by: Steve Clevenger <scclevenger at os.amperecomputing.com>
> ---
>   drivers/amba/bus.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
> index ff7454a38058..7c432442862c 100644
> --- a/drivers/amba/bus.c
> +++ b/drivers/amba/bus.c
> @@ -136,6 +136,7 @@ static int amba_read_periphid(struct amba_device *dev)
>   	u32 size, pid, cid;
>   	void __iomem *tmp;
>   	int i, ret;
> +	u32 cid_addr, pid_addr;
>   
>   	ret = dev_pm_domain_attach(&dev->dev, true);
>   	if (ret) {
> @@ -178,6 +179,12 @@ static int amba_read_periphid(struct amba_device *dev)
>   	for (cid = 0, i = 0; i < 4; i++)
>   		cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << (i * 8);
>   
> +	/* physical address as meaningful */
> +	cid_addr = (u64)(dev->res.start + size - 0x20);
> +	pid_addr = (u64)(dev->res.start + size - 0x10);
> +
> +	pr_debug("pid  (%llX): %08X  cid  (%llX): %08X\n", pid_addr, pid, cid_addr, cid);
> +
>   	if (cid == CORESIGHT_CID) {
>   		/* set the base to the start of the last 4k block */
>   		void __iomem *csbase = tmp + size - 4096;