Messages in this thread | | | Date | Wed, 31 Aug 2022 04:48:40 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH v3 02/19] hwmon: (mr75203) fix VM sensor allocation when "intel, vm-map" not defined |
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On 8/30/22 22:49, Farber, Eliav wrote: > On 8/31/2022 8:36 AM, Guenter Roeck wrote: >> On 8/30/22 12:21, Eliav Farber wrote: >>> Bug fix - in case "intel,vm-map" is missing in device-tree ,'num' is set >>> to 0, and no voltage channel infos are allocated. >>> >>> Signed-off-by: Eliav Farber <farbere@amazon.com> >>> --- >>> drivers/hwmon/mr75203.c | 28 ++++++++++++---------------- >>> 1 file changed, 12 insertions(+), 16 deletions(-) >>> >>> diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c >>> index 046523d47c29..0e29877a1a9c 100644 >>> --- a/drivers/hwmon/mr75203.c >>> +++ b/drivers/hwmon/mr75203.c >>> @@ -580,8 +580,6 @@ static int mr75203_probe(struct platform_device *pdev) >>> } >>> >>> if (vm_num) { >>> - u32 num = vm_num; >>> - >>> ret = pvt_get_regmap(pdev, "vm", pvt); >>> if (ret) >>> return ret; >>> @@ -594,30 +592,28 @@ static int mr75203_probe(struct platform_device *pdev) >>> ret = device_property_read_u8_array(dev, "intel,vm-map", >>> pvt->vm_idx, vm_num); >>> if (ret) { >>> - num = 0; >>> + /* >>> + * Incase intel,vm-map property is not defined, we >>> + * assume incremental channel numbers. >>> + */ >>> + for (i = 0; i < vm_num; i++) >>> + pvt->vm_idx[i] = i; >>> } else { >>> for (i = 0; i < vm_num; i++) >>> if (pvt->vm_idx[i] >= vm_num || >>> - pvt->vm_idx[i] == 0xff) { >>> - num = i; >>> + pvt->vm_idx[i] == 0xff) >>> break; >> >> So all vm_idx values from 0x00 to 0xfe would be acceptable ? >> Does the chip really have that many registers (0x200 + 0x40 + 0x200 * 0xfe) ? >> Is that documented somewhere ? > According to the code vm_num is limited to 32 because the mask is > only 5 bits: > > #define VM_NUM_MSK GENMASK(20, 16) > #define VM_NUM_SFT 16 > vm_num = (val & VM_NUM_MSK) >> VM_NUM_SFT; > > In practice according to the data sheet I have: > 0 <= VM instances <= 8 > Sorry, my bad. I misread the patch and thought the first part of the if statement was removed.
Anyway, what is the difference between specifying an vm_idx value of 0xff and not specifying anything ? Or, in other words, taking the dt example, the difference between intel,vm-map = [03 01 04 ff ff]; and intel,vm-map = [03 01 04];
Thanks, Guenter
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