Commit e146503a authored by Baskaran Kannan's avatar Baskaran Kannan Committed by Guenter Roeck
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hwmon: (k10temp) Enable AMD3255 Proc to show negative temperature 



Industrial processor i3255 supports temperatures -40 deg celcius
to 105 deg Celcius. The current implementation of k10temp_read_temp
rounds off any negative temperatures to '0'. To fix this,
the following changes have been made.

A flag 'disp_negative' is added to struct k10temp_data to support
AMD i3255 processors. Flag 'disp_negative' is set if 3255 processor
is found during k10temp_probe.  Flag 'disp_negative' is used to
determine whether to round off negative temperatures to '0' in
k10temp_read_temp.

Signed-off-by: default avatarBaskaran Kannan <Baski.Kannan@amd.com>
Link: https://lore.kernel.org/r/20230727162159.1056136-1-Baski.Kannan@amd.com


Fixes: aef17ca1 ("hwmon: (k10temp) Only apply temperature offset if result is positive")
Cc: stable@vger.kernel.org
[groeck: Fixed multi-line comment]
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent b84000f2

drivers/hwmon/k10temp.c

+15 −2
Original line number Diff line number Diff line
@@ -77,6 +77,13 @@ static DEFINE_MUTEX(nb_smu_ind_mutex); 
#define ZEN_CUR_TEMP_RANGE_SEL_MASK		BIT(19)

#define ZEN_CUR_TEMP_TJ_SEL_MASK		GENMASK(17, 16)



/*

 * AMD's Industrial processor 3255 supports temperature from -40 deg to 105 deg Celsius.

 * Use the model name to identify 3255 CPUs and set a flag to display negative temperature.

 * Do not round off to zero for negative Tctl or Tdie values if the flag is set

 */

#define AMD_I3255_STR				"3255"



struct k10temp_data {

	struct pci_dev *pdev;

	void (*read_htcreg)(struct pci_dev *pdev, u32 *regval);
@@ -86,6 +93,7 @@ struct k10temp_data { 
	u32 show_temp;

	bool is_zen;

	u32 ccd_offset;

	bool disp_negative;

};



#define TCTL_BIT	0
@@ -204,12 +212,12 @@ static int k10temp_read_temp(struct device *dev, u32 attr, int channel, 
		switch (channel) {

		case 0:		/* Tctl */

			*val = get_raw_temp(data);

			if (*val < 0)

			if (*val < 0 && !data->disp_negative)

				*val = 0;

			break;

		case 1:		/* Tdie */

			*val = get_raw_temp(data) - data->temp_offset;

			if (*val < 0)

			if (*val < 0 && !data->disp_negative)

				*val = 0;

			break;

		case 2 ... 13:		/* Tccd{1-12} */
@@ -405,6 +413,11 @@ static int k10temp_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	data->pdev = pdev;

	data->show_temp |= BIT(TCTL_BIT);	/* Always show Tctl */



	if (boot_cpu_data.x86 == 0x17 &&

	    strstr(boot_cpu_data.x86_model_id, AMD_I3255_STR)) {

		data->disp_negative = true;

	}



	if (boot_cpu_data.x86 == 0x15 &&

	    ((boot_cpu_data.x86_model & 0xf0) == 0x60 ||

	     (boot_cpu_data.x86_model & 0xf0) == 0x70)) {