Merge tag 'spi-fix-v6.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spiHEADmaster

Pull spi fixes from Mark Brown:
 "One final batch of fixes for the Tegra SPI drivers, the main one is a
  batch of fixes for races with the interrupts in the Tegra210 QSPI
  driver that Breno has been working on for a while"

* tag 'spi-fix-v6.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: tegra114: Preserve SPI mode bits in def_command1_reg
  spi: tegra: Fix a memory leak in tegra_slink_probe()
  spi: tegra210-quad: Protect curr_xfer check in IRQ handler
  spi: tegra210-quad: Protect curr_xfer clearing in tegra_qspi_non_combined_seq_xfer
  spi: tegra210-quad: Protect curr_xfer in tegra_qspi_combined_seq_xfer
  spi: tegra210-quad: Protect curr_xfer assignment in tegra_qspi_setup_transfer_one
  spi: tegra210-quad: Move curr_xfer read inside spinlock
  spi: tegra210-quad: Return IRQ_HANDLED when timeout already processed transfer

3 files changed, 59 insertions, 6 deletions

diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c
index 795a8482c2c7..48fb11fea55f 100644
--- a/drivers/spi/spi-tegra114.c
+++ b/drivers/spi/spi-tegra114.c
@@ -978,11 +978,14 @@ static int tegra_spi_setup(struct spi_device *spi)
 	if (spi_get_csgpiod(spi, 0))
 		gpiod_set_value(spi_get_csgpiod(spi, 0), 0);
 
+	/* Update default register to include CS polarity and SPI mode */
 	val = tspi->def_command1_reg;
 	if (spi->mode & SPI_CS_HIGH)
 		val &= ~SPI_CS_POL_INACTIVE(spi_get_chipselect(spi, 0));
 	else
 		val |= SPI_CS_POL_INACTIVE(spi_get_chipselect(spi, 0));
+	val &= ~SPI_CONTROL_MODE_MASK;
+	val |= SPI_MODE_SEL(spi->mode & 0x3);
 	tspi->def_command1_reg = val;
 	tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
 	spin_unlock_irqrestore(&tspi->lock, flags);
diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c
index fe452d03c1ee..709669610840 100644
--- a/drivers/spi/spi-tegra20-slink.c
+++ b/drivers/spi/spi-tegra20-slink.c
@@ -1086,8 +1086,10 @@ static int tegra_slink_probe(struct platform_device *pdev)
 	reset_control_deassert(tspi->rst);
 
 	spi_irq = platform_get_irq(pdev, 0);
-	if (spi_irq < 0)
-		return spi_irq;
+	if (spi_irq < 0) {
+		ret = spi_irq;
+		goto exit_pm_put;
+	}
 	tspi->irq = spi_irq;
 	ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
 				   tegra_slink_isr_thread, IRQF_ONESHOT,
diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index cdc3cb7c01f9..f425d62e0c27 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -839,6 +839,7 @@ static u32 tegra_qspi_setup_transfer_one(struct spi_device *spi, struct spi_tran
 	u32 command1, command2, speed = t->speed_hz;
 	u8 bits_per_word = t->bits_per_word;
 	u32 tx_tap = 0, rx_tap = 0;
+	unsigned long flags;
 	int req_mode;
 
 	if (!has_acpi_companion(tqspi->dev) && speed != tqspi->cur_speed) {
@@ -846,10 +847,12 @@ static u32 tegra_qspi_setup_transfer_one(struct spi_device *spi, struct spi_tran
 		tqspi->cur_speed = speed;
 	}
 
+	spin_lock_irqsave(&tqspi->lock, flags);
 	tqspi->cur_pos = 0;
 	tqspi->cur_rx_pos = 0;
 	tqspi->cur_tx_pos = 0;
 	tqspi->curr_xfer = t;
+	spin_unlock_irqrestore(&tqspi->lock, flags);
 
 	if (is_first_of_msg) {
 		tegra_qspi_mask_clear_irq(tqspi);
@@ -1158,6 +1161,7 @@ static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
 	u32 address_value = 0;
 	u32 cmd_config = 0, addr_config = 0;
 	u8 cmd_value = 0, val = 0;
+	unsigned long flags;
 
 	/* Enable Combined sequence mode */
 	val = tegra_qspi_readl(tqspi, QSPI_GLOBAL_CONFIG);
@@ -1261,13 +1265,17 @@ static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
 			tegra_qspi_transfer_end(spi);
 			spi_transfer_delay_exec(xfer);
 		}
+		spin_lock_irqsave(&tqspi->lock, flags);
 		tqspi->curr_xfer = NULL;
+		spin_unlock_irqrestore(&tqspi->lock, flags);
 		transfer_phase++;
 	}
 	ret = 0;
 
 exit:
+	spin_lock_irqsave(&tqspi->lock, flags);
 	tqspi->curr_xfer = NULL;
+	spin_unlock_irqrestore(&tqspi->lock, flags);
 	msg->status = ret;
 
 	return ret;
@@ -1280,6 +1288,7 @@ static int tegra_qspi_non_combined_seq_xfer(struct tegra_qspi *tqspi,
 	struct spi_transfer *transfer;
 	bool is_first_msg = true;
 	int ret = 0, val = 0;
+	unsigned long flags;
 
 	msg->status = 0;
 	msg->actual_length = 0;
@@ -1360,7 +1369,9 @@ static int tegra_qspi_non_combined_seq_xfer(struct tegra_qspi *tqspi,
 		msg->actual_length += xfer->len + dummy_bytes;
 
 complete_xfer:
+		spin_lock_irqsave(&tqspi->lock, flags);
 		tqspi->curr_xfer = NULL;
+		spin_unlock_irqrestore(&tqspi->lock, flags);
 
 		if (ret < 0) {
 			tegra_qspi_transfer_end(spi);
@@ -1440,10 +1451,16 @@ static int tegra_qspi_transfer_one_message(struct spi_controller *host,
 
 static irqreturn_t handle_cpu_based_xfer(struct tegra_qspi *tqspi)
 {
-	struct spi_transfer *t = tqspi->curr_xfer;
+	struct spi_transfer *t;
 	unsigned long flags;
 
 	spin_lock_irqsave(&tqspi->lock, flags);
+	t = tqspi->curr_xfer;
+
+	if (!t) {
+		spin_unlock_irqrestore(&tqspi->lock, flags);
+		return IRQ_HANDLED;
+	}
 
 	if (tqspi->tx_status ||  tqspi->rx_status) {
 		tegra_qspi_handle_error(tqspi);
@@ -1474,7 +1491,7 @@ exit:
 
 static irqreturn_t handle_dma_based_xfer(struct tegra_qspi *tqspi)
 {
-	struct spi_transfer *t = tqspi->curr_xfer;
+	struct spi_transfer *t;
 	unsigned int total_fifo_words;
 	unsigned long flags;
 	long wait_status;
@@ -1513,6 +1530,12 @@ static irqreturn_t handle_dma_based_xfer(struct tegra_qspi *tqspi)
 	}
 
 	spin_lock_irqsave(&tqspi->lock, flags);
+	t = tqspi->curr_xfer;
+
+	if (!t) {
+		spin_unlock_irqrestore(&tqspi->lock, flags);
+		return IRQ_HANDLED;
+	}
 
 	if (num_errors) {
 		tegra_qspi_dma_unmap_xfer(tqspi, t);
@@ -1552,15 +1575,33 @@ exit:
 static irqreturn_t tegra_qspi_isr_thread(int irq, void *context_data)
 {
 	struct tegra_qspi *tqspi = context_data;
+	unsigned long flags;
+	u32 status;
+
+	/*
+	 * Read transfer status to check if interrupt was triggered by transfer
+	 * completion
+	 */
+	status = tegra_qspi_readl(tqspi, QSPI_TRANS_STATUS);
 
 	/*
 	 * Occasionally the IRQ thread takes a long time to wake up (usually
 	 * when the CPU that it's running on is excessively busy) and we have
 	 * already reached the timeout before and cleaned up the timed out
 	 * transfer. Avoid any processing in that case and bail out early.
+	 *
+	 * If no transfer is in progress, check if this was a real interrupt
+	 * that the timeout handler already processed, or a spurious one.
 	 */
-	if (!tqspi->curr_xfer)
-		return IRQ_NONE;
+	spin_lock_irqsave(&tqspi->lock, flags);
+	if (!tqspi->curr_xfer) {
+		spin_unlock_irqrestore(&tqspi->lock, flags);
+		/* Spurious interrupt - transfer not ready */
+		if (!(status & QSPI_RDY))
+			return IRQ_NONE;
+		/* Real interrupt, already handled by timeout path */
+		return IRQ_HANDLED;
+	}
 
 	tqspi->status_reg = tegra_qspi_readl(tqspi, QSPI_FIFO_STATUS);
 
@@ -1571,7 +1612,14 @@ static irqreturn_t tegra_qspi_isr_thread(int irq, void *context_data)
 		tqspi->rx_status = tqspi->status_reg & (QSPI_RX_FIFO_OVF | QSPI_RX_FIFO_UNF);
 
 	tegra_qspi_mask_clear_irq(tqspi);
+	spin_unlock_irqrestore(&tqspi->lock, flags);
 
+	/*
+	 * Lock is released here but handlers safely re-check curr_xfer under
+	 * lock before dereferencing.
+	 * DMA handler also needs to sleep in wait_for_completion_*(), which
+	 * cannot be done while holding spinlock.
+	 */
 	if (!tqspi->is_curr_dma_xfer)
 		return handle_cpu_based_xfer(tqspi);