Hi,
On 20-11-18 16:59, Andy Shevchenko wrote:
Instead of relying on hard coded and thus expected number of I2C clients,
count the real amount provided by firmware.
This allows to support non-fixed amount of the slaves.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/platform/x86/i2c-multi-instantiate.c | 34 ++++++++++++++++++--
1 file changed, 31 insertions(+), 3 deletions(-)
diff --git a/drivers/platform/x86/i2c-multi-instantiate.c b/drivers/platform/x86/i2c-multi-instantiate.c
index 16a0eabe1e31..d17686e10d08 100644
--- a/drivers/platform/x86/i2c-multi-instantiate.c
+++ b/drivers/platform/x86/i2c-multi-instantiate.c
@@ -12,6 +12,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/types.h>
struct i2c_inst_data {
const char *type;
@@ -23,6 +24,31 @@ struct i2c_multi_inst_data {
struct i2c_client *clients[0];
};
+static int i2c_multi_inst_count(struct acpi_resource *ares, void *data)
+{
+ struct acpi_resource_i2c_serialbus *sb;
+ int *count = data;
+
+ if (i2c_acpi_get_i2c_resource(ares, &sb))
+ *count = *count + 1;
+
+ return 1;
+}
+
+static int i2c_multi_inst_count_resources(struct acpi_device *adev)
+{
+ LIST_HEAD(r);
+ int count = 0;
+ int ret;
+
+ ret = acpi_dev_get_resources(adev, &r, i2c_multi_inst_count, &count);
+ if (ret < 0)
+ return ret;
+
+ acpi_dev_free_resource_list(&r);
+ return count;
+}
+
static int i2c_multi_inst_probe(struct platform_device *pdev)
{
struct i2c_multi_inst_data *multi;
@@ -44,15 +70,17 @@ static int i2c_multi_inst_probe(struct platform_device *pdev)
adev = ACPI_COMPANION(dev);
/* Count number of clients to instantiate */
- for (i = 0; inst_data[i].type; i++) {}
+ ret = i2c_multi_inst_count_resources(adev);
+ if (ret < 0)
+ return ret;
multi = devm_kmalloc(dev,
- offsetof(struct i2c_multi_inst_data, clients[i]),
+ offsetof(struct i2c_multi_inst_data, clients[ret]),
GFP_KERNEL);
if (!multi)
return -ENOMEM;
- multi->num_clients = i;
+ multi->num_clients = ret;
for (i = 0; i < multi->num_clients; i++) {
memset(&board_info, 0, sizeof(board_info));
Now you end up indexing inst_data with i without checking that inst_data
holds enough data. Not using all of inst_data in case there are less
I2cSerialBus resources then inst_data entries is fine. But you need to
deal with the case when there are more I2cSerialBus resources then inst_data
entries, either by erroring out or ignoring the extra I2cSerialBus resources.
Also it might be better to make the i2c_multi_inst_count_resources() function
a generic helper under drivers/acpi, so that it can be used in other places,
see my comments to the BOSC0200 patch.
Regards,
Hans
