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From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Bartosz Golaszewski <bartosz.golaszewski@linaro.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Linus Walleij <linus.walleij@linaro.org>,
        Alexander Stein <alexander.stein@ew.tq-group.com>,
        linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org
Cc:     Bartosz Golaszewski <brgl@bgdev.pl>,
        Andy Shevchenko <andy@kernel.org>
Subject: [PATCH v3 3/5] gpio: aggregator: Prevent collisions between DT and user device IDs
Date:   Thu, 15 Jun 2023 16:20:21 +0300
Message-Id: <20230615132023.13801-4-andriy.shevchenko@linux.intel.com>
In-Reply-To: <20230615132023.13801-1-andriy.shevchenko@linux.intel.com>
References: <20230615132023.13801-1-andriy.shevchenko@linux.intel.com>
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In case we have a device instantiated via DT or other means than
via new_device sysfs node, the collision with the latter is possible.
Prevent such collisions by allocating user instantiated devices with
higher IDs, currently set to 1024.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/gpio/gpio-aggregator.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index 4a470dd8b75d..8892cb37ad79 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -26,6 +26,7 @@
 #include <linux/gpio/driver.h>
 #include <linux/gpio/machine.h>
 
+#define AGGREGATOR_MIN_DEVID 1024
 #define AGGREGATOR_MAX_GPIOS 512
 
 /*
@@ -135,7 +136,7 @@ static ssize_t new_device_store(struct device_driver *driver, const char *buf,
 	}
 
 	mutex_lock(&gpio_aggregator_lock);
-	id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL);
+	id = idr_alloc(&gpio_aggregator_idr, aggr, AGGREGATOR_MIN_DEVID, 0, GFP_KERNEL);
 	mutex_unlock(&gpio_aggregator_lock);
 
 	if (id < 0) {
-- 
2.40.0.1.gaa8946217a0b