Re: [PATCH 2/2] leds: simatic-ipc-leds: Don't directly deref ioremap_resource() returned ptr

[Henning Schild <henning.schild@siemens.com>]

Hi Hans,

this looks fine but also looks like someone should test it. What is the
timeline on that? I would want that tested but will need a few more
days to actually sit next to boxes and look at LEDs.

Gerd maybe you can try that? Should affect 127E only and can probably
be applied onto our out-of-tree repo.

regards,
Henning

Am Mon, 17 Jan 2022 12:21:09 +0100
schrieb Hans de Goede <hdegoede@redhat.com>:

> Sparse (rightly) currently gives the following warning:
> 
> drivers/leds/simple/simatic-ipc-leds.c:155:40:
>  sparse: sparse: incorrect type in assignment (different address
> spaces) expected void *static [toplevel] simatic_ipc_led_memory
>  got void [noderef] __iomem *
> 
> Fix this by changing the type of simatic_ipc_led_memory to void
> __iomem * and use readl()/writel() to access it.
> 
> Cc: Henning Schild <henning.schild@siemens.com>
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Note this is not tested on actual hw, since I do not have the hw in
> question ---
>  drivers/leds/simple/simatic-ipc-leds.c | 32
> +++++++++++++++----------- 1 file changed, 18 insertions(+), 14
> deletions(-)
> 
> diff --git a/drivers/leds/simple/simatic-ipc-leds.c
> b/drivers/leds/simple/simatic-ipc-leds.c index
> 179110448659..078d43f5ba38 100644 ---
> a/drivers/leds/simple/simatic-ipc-leds.c +++
> b/drivers/leds/simple/simatic-ipc-leds.c @@ -41,7 +41,7 @@ static
> struct simatic_ipc_led simatic_ipc_leds_io[] = { /* the actual start
> will be discovered with PCI, 0 is a placeholder */ static struct
> resource simatic_ipc_led_mem_res = DEFINE_RES_MEM_NAMED(0, SZ_4K,
> KBUILD_MODNAME); -static void *simatic_ipc_led_memory;
> +static void __iomem *simatic_ipc_led_memory;
>  
>  static struct simatic_ipc_led simatic_ipc_leds_mem[] = {
>  	{0x500 + 0x1A0, "red:" LED_FUNCTION_STATUS "-1"},
> @@ -92,21 +92,22 @@ static void simatic_ipc_led_set_mem(struct
> led_classdev *led_cd, enum led_brightness brightness)
>  {
>  	struct simatic_ipc_led *led = cdev_to_led(led_cd);
> +	void __iomem *reg = simatic_ipc_led_memory + led->value;
> +	u32 val;
>  
> -	u32 *p;
> -
> -	p = simatic_ipc_led_memory + led->value;
> -	*p = (*p & ~1) | (brightness == LED_OFF);
> +	val = readl(reg);
> +	val = (val & ~1) | (brightness == LED_OFF);
> +	writel(val, reg);
>  }
>  
>  static enum led_brightness simatic_ipc_led_get_mem(struct
> led_classdev *led_cd) {
>  	struct simatic_ipc_led *led = cdev_to_led(led_cd);
> +	void __iomem *reg = simatic_ipc_led_memory + led->value;
> +	u32 val;
>  
> -	u32 *p;
> -
> -	p = simatic_ipc_led_memory + led->value;
> -	return (*p & 1) ? LED_OFF : led_cd->max_brightness;
> +	val = readl(reg);
> +	return (val & 1) ? LED_OFF : led_cd->max_brightness;
>  }
>  
>  static int simatic_ipc_leds_probe(struct platform_device *pdev)
> @@ -116,8 +117,9 @@ static int simatic_ipc_leds_probe(struct
> platform_device *pdev) struct simatic_ipc_led *ipcled;
>  	struct led_classdev *cdev;
>  	struct resource *res;
> +	void __iomem *reg;
>  	int err, type;
> -	u32 *p;
> +	u32 val;
>  
>  	switch (plat->devmode) {
>  	case SIMATIC_IPC_DEVICE_227D:
> @@ -157,11 +159,13 @@ static int simatic_ipc_leds_probe(struct
> platform_device *pdev) return PTR_ERR(simatic_ipc_led_memory);
>  
>  		/* initialize power/watchdog LED */
> -		p = simatic_ipc_led_memory + 0x500 + 0x1D8; /*
> PM_WDT_OUT */
> -		*p = (*p & ~1);
> -		p = simatic_ipc_led_memory + 0x500 + 0x1C0; /*
> PM_BIOS_BOOT_N */
> -		*p = (*p | 1);
> +		reg = simatic_ipc_led_memory + 0x500 + 0x1D8; /*
> PM_WDT_OUT */
> +		val = readl(reg);
> +		writel(val & ~1, reg);
>  
> +		reg = simatic_ipc_led_memory + 0x500 + 0x1C0; /*
> PM_BIOS_BOOT_N */
> +		val = readl(reg);
> +		writel(val | 1, reg);
>  		break;
>  	default:
>  		return -ENODEV;