--- /dev/null
+From 78b2d9bbb63b52361ee79b15bc32c1d5bfd02385 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Mon, 11 Dec 2023 17:22:16 +0700
+Subject: i2c: aspeed: Handle the coalesced stop conditions with the start
+ conditions.
+
+From: Quan Nguyen <quan@os.amperecomputing.com>
+
+[ Upstream commit b4cc1cbba5195a4dd497cf2f8f09e7807977d543 ]
+
+Some masters may drive the transfers with low enough latency between
+the nak/stop phase of the current command and the start/address phase
+of the following command that the interrupts are coalesced by the
+time we process them.
+Handle the stop conditions before processing SLAVE_MATCH to fix the
+complaints that sometimes occur below.
+
+"aspeed-i2c-bus 1e78a040.i2c-bus: irq handled != irq. Expected
+0x00000086, but was 0x00000084"
+
+Fixes: f9eb91350bb2 ("i2c: aspeed: added slave support for Aspeed I2C driver")
+Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
+Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au>
+Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
+Signed-off-by: Wolfram Sang <wsa@kernel.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/i2c/busses/i2c-aspeed.c | 48 ++++++++++++++++++++++-----------
+ 1 file changed, 32 insertions(+), 16 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
+index ff08bcb09a68e..3f0b072a4cc84 100644
+--- a/drivers/i2c/busses/i2c-aspeed.c
++++ b/drivers/i2c/busses/i2c-aspeed.c
+@@ -250,18 +250,46 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
+ if (!slave)
+ return 0;
+
+- command = readl(bus->base + ASPEED_I2C_CMD_REG);
++ /*
++ * Handle stop conditions early, prior to SLAVE_MATCH. Some masters may drive
++ * transfers with low enough latency between the nak/stop phase of the current
++ * command and the start/address phase of the following command that the
++ * interrupts are coalesced by the time we process them.
++ */
++ if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) {
++ irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP;
++ bus->slave_state = ASPEED_I2C_SLAVE_STOP;
++ }
++
++ if (irq_status & ASPEED_I2CD_INTR_TX_NAK &&
++ bus->slave_state == ASPEED_I2C_SLAVE_READ_PROCESSED) {
++ irq_handled |= ASPEED_I2CD_INTR_TX_NAK;
++ bus->slave_state = ASPEED_I2C_SLAVE_STOP;
++ }
++
++ /* Propagate any stop conditions to the slave implementation. */
++ if (bus->slave_state == ASPEED_I2C_SLAVE_STOP) {
++ i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
++ bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE;
++ }
+
+- /* Slave was requested, restart state machine. */
++ /*
++ * Now that we've dealt with any potentially coalesced stop conditions,
++ * address any start conditions.
++ */
+ if (irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH) {
+ irq_handled |= ASPEED_I2CD_INTR_SLAVE_MATCH;
+ bus->slave_state = ASPEED_I2C_SLAVE_START;
+ }
+
+- /* Slave is not currently active, irq was for someone else. */
++ /*
++ * If the slave has been stopped and not started then slave interrupt
++ * handling is complete.
++ */
+ if (bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE)
+ return irq_handled;
+
++ command = readl(bus->base + ASPEED_I2C_CMD_REG);
+ dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n",
+ irq_status, command);
+
+@@ -280,17 +308,6 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
+ irq_handled |= ASPEED_I2CD_INTR_RX_DONE;
+ }
+
+- /* Slave was asked to stop. */
+- if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) {
+- irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP;
+- bus->slave_state = ASPEED_I2C_SLAVE_STOP;
+- }
+- if (irq_status & ASPEED_I2CD_INTR_TX_NAK &&
+- bus->slave_state == ASPEED_I2C_SLAVE_READ_PROCESSED) {
+- irq_handled |= ASPEED_I2CD_INTR_TX_NAK;
+- bus->slave_state = ASPEED_I2C_SLAVE_STOP;
+- }
+-
+ switch (bus->slave_state) {
+ case ASPEED_I2C_SLAVE_READ_REQUESTED:
+ if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_ACK))
+@@ -319,8 +336,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
+ i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value);
+ break;
+ case ASPEED_I2C_SLAVE_STOP:
+- i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
+- bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE;
++ /* Stop event handling is done early. Unreachable. */
+ break;
+ case ASPEED_I2C_SLAVE_START:
+ /* Slave was just started. Waiting for the next event. */;
+--
+2.43.0
+
--- /dev/null
+From 3f0156c96c9bb6b54f0e8f6950ba6e8534643dc0 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Fri, 15 Dec 2023 22:34:24 +0100
+Subject: pinctrl: at91-pio4: use dedicated lock class for IRQ
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Alexis Lothoré <alexis.lothore@bootlin.com>
+
+[ Upstream commit 14694179e561b5f2f7e56a0f590e2cb49a9cc7ab ]
+
+Trying to suspend to RAM on SAMA5D27 EVK leads to the following lockdep
+warning:
+
+ ============================================
+ WARNING: possible recursive locking detected
+ 6.7.0-rc5-wt+ #532 Not tainted
+ --------------------------------------------
+ sh/92 is trying to acquire lock:
+ c3cf306c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
+
+ but task is already holding lock:
+ c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
+
+ other info that might help us debug this:
+ Possible unsafe locking scenario:
+
+ CPU0
+ ----
+ lock(&irq_desc_lock_class);
+ lock(&irq_desc_lock_class);
+
+ *** DEADLOCK ***
+
+ May be due to missing lock nesting notation
+
+ 6 locks held by sh/92:
+ #0: c3aa0258 (sb_writers#6){.+.+}-{0:0}, at: ksys_write+0xd8/0x178
+ #1: c4c2df44 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x138/0x284
+ #2: c32684a0 (kn->active){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x148/0x284
+ #3: c232b6d4 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x13c/0x4e8
+ #4: c387b088 (&dev->mutex){....}-{3:3}, at: __device_suspend+0x1e8/0x91c
+ #5: c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
+
+ stack backtrace:
+ CPU: 0 PID: 92 Comm: sh Not tainted 6.7.0-rc5-wt+ #532
+ Hardware name: Atmel SAMA5
+ unwind_backtrace from show_stack+0x18/0x1c
+ show_stack from dump_stack_lvl+0x34/0x48
+ dump_stack_lvl from __lock_acquire+0x19ec/0x3a0c
+ __lock_acquire from lock_acquire.part.0+0x124/0x2d0
+ lock_acquire.part.0 from _raw_spin_lock_irqsave+0x5c/0x78
+ _raw_spin_lock_irqsave from __irq_get_desc_lock+0xe8/0x100
+ __irq_get_desc_lock from irq_set_irq_wake+0xa8/0x204
+ irq_set_irq_wake from atmel_gpio_irq_set_wake+0x58/0xb4
+ atmel_gpio_irq_set_wake from irq_set_irq_wake+0x100/0x204
+ irq_set_irq_wake from gpio_keys_suspend+0xec/0x2b8
+ gpio_keys_suspend from dpm_run_callback+0xe4/0x248
+ dpm_run_callback from __device_suspend+0x234/0x91c
+ __device_suspend from dpm_suspend+0x224/0x43c
+ dpm_suspend from dpm_suspend_start+0x9c/0xa8
+ dpm_suspend_start from suspend_devices_and_enter+0x1e0/0xa84
+ suspend_devices_and_enter from pm_suspend+0x460/0x4e8
+ pm_suspend from state_store+0x78/0xe4
+ state_store from kernfs_fop_write_iter+0x1a0/0x284
+ kernfs_fop_write_iter from vfs_write+0x38c/0x6f4
+ vfs_write from ksys_write+0xd8/0x178
+ ksys_write from ret_fast_syscall+0x0/0x1c
+ Exception stack(0xc52b3fa8 to 0xc52b3ff0)
+ 3fa0: 00000004 005a0ae8 00000001 005a0ae8 00000004 00000001
+ 3fc0: 00000004 005a0ae8 00000001 00000004 00000004 b6c616c0 00000020 0059d190
+ 3fe0: 00000004 b6c61678 aec5a041 aebf1a26
+
+This warning is raised because pinctrl-at91-pio4 uses chained IRQ. Whenever
+a wake up source configures an IRQ through irq_set_irq_wake, it will
+lock the corresponding IRQ desc, and then call irq_set_irq_wake on "parent"
+IRQ which will do the same on its own IRQ desc, but since those two locks
+share the same class, lockdep reports this as an issue.
+
+Fix lockdep false positive by setting a different class for parent and
+children IRQ
+
+Fixes: 776180848b57 ("pinctrl: introduce driver for Atmel PIO4 controller")
+Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
+Link: https://lore.kernel.org/r/20231215-lockdep_warning-v1-1-8137b2510ed5@bootlin.com
+Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/pinctrl/pinctrl-at91-pio4.c | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
+index 9c225256e3f4e..409506c1de144 100644
+--- a/drivers/pinctrl/pinctrl-at91-pio4.c
++++ b/drivers/pinctrl/pinctrl-at91-pio4.c
+@@ -928,6 +928,13 @@ static const struct of_device_id atmel_pctrl_of_match[] = {
+ }
+ };
+
++/*
++ * This lock class allows to tell lockdep that parent IRQ and children IRQ do
++ * not share the same class so it does not raise false positive
++ */
++static struct lock_class_key atmel_lock_key;
++static struct lock_class_key atmel_request_key;
++
+ static int atmel_pinctrl_probe(struct platform_device *pdev)
+ {
+ struct device *dev = &pdev->dev;
+@@ -1078,6 +1085,7 @@ static int atmel_pinctrl_probe(struct platform_device *pdev)
+ irq_set_chip_and_handler(irq, &atmel_gpio_irq_chip,
+ handle_simple_irq);
+ irq_set_chip_data(irq, atmel_pioctrl);
++ irq_set_lockdep_class(irq, &atmel_lock_key, &atmel_request_key);
+ dev_dbg(dev,
+ "atmel gpio irq domain: hwirq: %d, linux irq: %d\n",
+ i, irq);
+--
+2.43.0
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
