Re: [PATCH v3] drm/xe/i2c: Expose AMC Alert reason sysfs

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 01-10-2026 17:37, sashiko-bot@kernel.org wrote:
>> +/**
>> + * DOC: AMC Alert Reason
>> + *
>> + * Expose AMC alert reason through device sysfs
>> + *
>> + * See Documentation/ABI/testing/sysfs-driver-intel-xe-amc for the ABI
>> + * specification.
>> + */
>> +
>> +static ssize_t amc_alert_reason_show(struct device *dev,
>> +				     struct device_attribute *attr, char *buf)
>> +{
>> +	struct xe_device *xe = pdev_to_xe_device(to_pci_dev(dev));
>> +	struct xe_amc *amc = xe->i2c->amc;
>> +	u8 alert_reason;
>> +
>> +	if (!amc->alert_seen)
> [Severity: Medium]
> Could this read of amc->alert_seen cause a data race?
>
> The sysfs reader relies on this boolean flag to decide whether to read
> alert_reason, but it lacks memory barriers or READ_ONCE(). A concurrent
> sysfs reader might observe an inconsistent state here while a new alert
> is being processed.

|alert_seen is not intended as a synchronization mechanism. |
|It only distinguishes the initial state where no AMC alert has been 
received. |
|The sysfs attribute is expected to be queried after the device is 
declared wedged, by which point the alert state has already been recorded.|