+++ /dev/null
-From: David Bauer <mail@david-bauer.net>
-Date: Tue, 2 Jan 2025 19:22:40 +0100
-Subject: [PATCH] reset: ath79: reset ETH switch for AR9344
-
-According to datasheet, on AR9344 the switch and switch analog need to
-be reset first before initiating a full reset.
-
-Resetting these systems fixes spurious reset hangs on Atheros AR9344
-SoCs.
-
-Link: https://github.com/freifunk-gluon/gluon/issues/2904
-
-Signed-off-by: David Bauer <mail@david-bauer.net>
-
---- a/drivers/reset/reset-ath79.c
-+++ b/drivers/reset/reset-ath79.c
-@@ -12,8 +12,11 @@
- #include <linux/platform_device.h>
- #include <linux/reset-controller.h>
- #include <linux/reboot.h>
-+#include <linux/delay.h>
-+#include <linux/of.h>
-
- struct ath79_reset {
-+ struct platform_device *pdev;
- struct reset_controller_dev rcdev;
- struct notifier_block restart_nb;
- void __iomem *base;
-@@ -21,16 +24,13 @@ struct ath79_reset {
- };
-
- #define FULL_CHIP_RESET 24
-+#define ETH_SWITCH_RESET 8
-+#define ETH_SWITCH_ARESET 12
-
--static int ath79_reset_update(struct reset_controller_dev *rcdev,
-+static void __ath79_reset_update_unlocked(struct ath79_reset *ath79_reset,
- unsigned long id, bool assert)
- {
-- struct ath79_reset *ath79_reset =
-- container_of(rcdev, struct ath79_reset, rcdev);
-- unsigned long flags;
- u32 val;
--
-- spin_lock_irqsave(&ath79_reset->lock, flags);
- val = readl(ath79_reset->base);
- if (assert)
- val |= BIT(id);
-@@ -39,6 +39,17 @@ static int ath79_reset_update(struct res
- writel(val, ath79_reset->base);
- /* Flush cache */
- readl(ath79_reset->base);
-+}
-+
-+static int ath79_reset_update(struct reset_controller_dev *rcdev,
-+ unsigned long id, bool assert)
-+{
-+ struct ath79_reset *ath79_reset =
-+ container_of(rcdev, struct ath79_reset, rcdev);
-+ unsigned long flags;
-+
-+ spin_lock_irqsave(&ath79_reset->lock, flags);
-+ __ath79_reset_update_unlocked(ath79_reset, id, assert);
- spin_unlock_irqrestore(&ath79_reset->lock, flags);
-
- return 0;
-@@ -79,8 +90,27 @@ static int ath79_reset_restart_handler(s
- {
- struct ath79_reset *ath79_reset =
- container_of(nb, struct ath79_reset, restart_nb);
-+ unsigned long flags;
-
-- ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
-+ spin_lock_irqsave(&ath79_reset->lock, flags);
-+
-+ if (of_device_is_compatible(ath79_reset->pdev->dev.of_node, "qca,ar9340-reset")) {
-+ /**
-+ * AR9344 has been observed to hang on reboot in rare cases.
-+ *
-+ * Datasheet states to reset the ETH switch systems before asserting
-+ * full chip reset. See page 111 of the AR9344 datasheet.
-+ */
-+ __ath79_reset_update_unlocked(ath79_reset, ETH_SWITCH_RESET, true);
-+ mdelay(10);
-+ __ath79_reset_update_unlocked(ath79_reset, ETH_SWITCH_ARESET, true);
-+ mdelay(10);
-+ }
-+
-+ __ath79_reset_update_unlocked(ath79_reset, FULL_CHIP_RESET, true);
-+ mdelay(10);
-+
-+ spin_unlock_irqrestore(&ath79_reset->lock, flags);
-
- return NOTIFY_DONE;
- }
-@@ -95,6 +125,8 @@ static int ath79_reset_probe(struct plat
- if (!ath79_reset)
- return -ENOMEM;
-
-+ ath79_reset->pdev = pdev;
-+
- ath79_reset->base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(ath79_reset->base))
- return PTR_ERR(ath79_reset->base);