On 8/31/2022 2:48 PM, Guenter Roeck wrote:
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@xxxxxxxxxx>
---
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];
The actual number of VMs is read from a HW register:
ret = regmap_read(pvt->c_map, PVT_IP_CONFIG, &val);
...
vm_num = (val & VM_NUM_MSK) >> VM_NUM_SFT;
Also, using:
ret = device_property_read_u8_array(dev, "intel,vm-map", vm_idx,
vm_num);
in the driver will fail if vm_num > sizeof array in device-tree.
So, if for example vm_num = 5, but you will want to map only 3 of them
you most set property to be:
intel,vm-map = [03 01 04 ff ff];
otherwise if you set:
intel,vm-map = [03 01 04];
it will assume the property doesn't, and will continue the flow in code
as if it doesn’t exist (which is not what the user wanted, and before my
fix also has a bug).
--
Regards, Eliav
