On Sat, May 9, 2020 at 1:50 AM Raul E Rangel <rrangel@xxxxxxxxxxxx> wrote:
>
> acpi_dev_hid_uid_match expects a null pointer for UID if it doesn't
acpi_dev_hid_uid_match()
> exist. The acpihid_map_entry contains a char buffer for holding the
> UID. If no UID was provided in the IVRS table, this buffer will be
> zeroed. If we pass in a null string, acpi_dev_hid_uid_match will return
acpi_dev_hid_uid_match()
> false because it will try and match an empty string to the ACPI UID of
> the device.
Thank you for testing and producing a patch! My comments below, after addressing
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
>
> Fixes: ae5e6c6439c3 ("iommu/amd: Switch to use acpi_dev_hid_uid_match()")
Suggested-by?
> Signed-off-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>
> ---
>
> drivers/iommu/amd_iommu.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index 20cce366e951..06f603366cb1 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -125,7 +125,8 @@ static inline int get_acpihid_device_id(struct device *dev,
> return -ENODEV;
>
> list_for_each_entry(p, &acpihid_map, list) {
> - if (acpi_dev_hid_uid_match(adev, p->hid, p->uid)) {
> + if (acpi_dev_hid_uid_match(adev, p->hid,
> + p->uid[0] ? p->uid : NULL)) {
I would still use *p->uid as done in other places in the driver and
put this all on one line (however, the latter is complete style
preference depending on maintainer's choice)
> if (entry)
> *entry = p;
> return p->devid;
> --
> 2.26.2.645.ge9eca65c58-goog
>
--
With Best Regards,
Andy Shevchenko
