linux-kernel - Re: [PATCH v1 08/12] nvmem: microchip-otpc: Add warnings for bad OTPC conditions on probe

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Message-ID: <5d2a6498-57c5-4fb4-9a68-e35072f4b8e3@tuxon.dev>
Date: Sat, 24 Aug 2024 18:51:46 +0300
From: claudiu beznea <claudiu.beznea@...on.dev>
To: Alexander Dahl <ada@...rsis.com>
Cc: Christian Melki <christian.melki@...ata.com>,
 Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
 "moderated list:MICROCHIP OTPC DRIVER"
 <linux-arm-kernel@...ts.infradead.org>,
 open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1 08/12] nvmem: microchip-otpc: Add warnings for bad OTPC
 conditions on probe



On 21.08.2024 13:59, Alexander Dahl wrote:
> These conditions could affect correct function of the driver.

Can you please detail why this has been added, what was the issue you
identified etc?

> 
> Signed-off-by: Alexander Dahl <ada@...rsis.com>
> ---
>  drivers/nvmem/microchip-otpc.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/nvmem/microchip-otpc.c b/drivers/nvmem/microchip-otpc.c
> index 4630e96243ac..a80535c3d162 100644
> --- a/drivers/nvmem/microchip-otpc.c
> +++ b/drivers/nvmem/microchip-otpc.c
> @@ -8,6 +8,7 @@
>   */
>  
>  #include <linux/bitfield.h>
> +#include <linux/dev_printk.h>
>  #include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/nvmem-provider.h>
> @@ -260,6 +261,7 @@ static int mchp_otpc_probe(struct platform_device *pdev)
>  	struct nvmem_device *nvmem;
>  	struct mchp_otpc *otpc;
>  	u32 size;
> +	u32 reg;
>  	int ret;
>  
>  	otpc = devm_kzalloc(&pdev->dev, sizeof(*otpc), GFP_KERNEL);
> @@ -270,6 +272,16 @@ static int mchp_otpc_probe(struct platform_device *pdev)
>  	if (IS_ERR(otpc->base))
>  		return PTR_ERR(otpc->base);
>  
> +	reg = readl_relaxed(otpc->base + MCHP_OTPC_WPSR);
> +	if (reg)
> +		dev_warn(&pdev->dev,
> +			 "Write Protection Status Register Bit set: 0x%08x\n", reg);

There are many status bits in WPSR. Some of these bits suggests warnings
even when their values are zero (e.g., ECLASS, SWETYP). I don't know how
accurate is this message.


> +
> +	reg = readl_relaxed(otpc->base + MCHP_OTPC_ISR);
> +	if (reg & MCHP_OTPC_ISR_COERR)
> +		dev_warn(&pdev->dev,
> +			 "A corruption occurred since the last read of OTPC_ISR.\n");
> +
>  	otpc->dev = &pdev->dev;
>  	ret = mchp_otpc_init_packets_list(otpc, &size);
>  	if (ret)