Re: [PATCH v2 03/16] ACPI: property: Rework acpi_graph_get_next_endpoint()
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2025-09-24 09:40:10
Also in:
linux-acpi, linux-leds, linux-media, linux-spi, lkml, netdev
Hi Sakari, On Wed, Sep 24, 2025 at 10:45:49AM +0300, Sakari Ailus wrote:
quoted hunk ↗ jump to hunk
Rework the code obtaining the next endpoint in acpi_graph_get_next_endpoint(). The resulting code removes unnecessary contitionals and should be easier to follow. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> --- drivers/acpi/property.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index 3e85900080ac..5438592dc136 100644 --- a/drivers/acpi/property.c +++ b/drivers/acpi/property.c@@ -1399,14 +1399,15 @@ static struct fwnode_handle *acpi_graph_get_next_endpoint( if (!port) return NULL; - endpoint = acpi_get_next_subnode(port, prev); - while (!endpoint) { - port = acpi_get_next_subnode(fwnode, port); - if (!port) + do { + endpoint = acpi_get_next_subnode(port, prev); + if (endpoint) break; + + port = acpi_get_next_subnode(fwnode, port); if (is_acpi_graph_node(port, "port")) - endpoint = acpi_get_next_subnode(port, NULL); - } + prev = NULL;
Isn't there an issue here ? If the next subnode of fwnode is not a port,
the next iteration of the do loop will attempt to get an endpoint from
that non-port node. Maybe the acpi_get_next_subnode() that will try to
get the endpoint from the non-port port will return NULL because prev
won't be a child of port, but that seems fragile.
I think the following would be easier to understand:
do {
endpoint = acpi_get_next_subnode(port, prev);
if (endpoint)
break;
prev = NULL;
do {
port = acpi_get_next_subnode(fwnode, port);
} while (port && !is_acpi_graph_node(port, "port"));
} while (port);
+ } while (port); /* * The names of the endpoint nodes begin with "endpoint@" followed by
-- Regards, Laurent Pinchart