[PATCH v4 1/6] tpm, tpm_tis_spi: Request threaded irq

[Lino Sanfilippo]

From: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>

Interrupt handling at least includes reading and writing the interrupt
status register within the interrupt routine. Since accesses over the SPI
bus are synchronized by a mutex, request a threaded interrupt handler to
ensure a sleepable context during interrupt processing.

Fixes: 1a339b658d9d ("tpm_tis_spi: Pass the SPI IRQ down to the driver")
Signed-off-by: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>
---
 drivers/char/tpm/tpm_tis_core.c     | 15 +++++++++++++--
 drivers/char/tpm/tpm_tis_core.h     |  1 +
 drivers/char/tpm/tpm_tis_spi_main.c |  5 +++--
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index dc56b976d816..52369ef39b03 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -747,8 +747,19 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
 	int rc;
 	u32 int_status;
 
-	if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
-			     dev_name(&chip->dev), chip) != 0) {
+
+	if (priv->flags & TPM_TIS_USE_THREADED_IRQ) {
+		rc = devm_request_threaded_irq(chip->dev.parent, irq, NULL,
+					       tis_int_handler,
+					       IRQF_ONESHOT | flags,
+					       dev_name(&chip->dev),
+					       chip);
+	} else {
+		rc = devm_request_irq(chip->dev.parent, irq, tis_int_handler,
+				      flags, dev_name(&chip->dev), chip);
+	}
+
+	if (rc) {
 		dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
 			 irq);
 		return -1;
diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h
index 3be24f221e32..43b724e55192 100644
--- a/drivers/char/tpm/tpm_tis_core.h
+++ b/drivers/char/tpm/tpm_tis_core.h
@@ -86,6 +86,7 @@ enum tis_defaults {
 enum tpm_tis_flags {
 	TPM_TIS_ITPM_WORKAROUND		= BIT(0),
 	TPM_TIS_INVALID_STATUS		= BIT(1),
+	TPM_TIS_USE_THREADED_IRQ	= BIT(2),
 };
 
 struct tpm_tis_data {
diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c
index 184396b3af50..f56613f2946f 100644
--- a/drivers/char/tpm/tpm_tis_spi_main.c
+++ b/drivers/char/tpm/tpm_tis_spi_main.c
@@ -223,9 +223,10 @@ static int tpm_tis_spi_probe(struct spi_device *dev)
 	phy->flow_control = tpm_tis_spi_flow_control;
 
 	/* If the SPI device has an IRQ then use that */
-	if (dev->irq > 0)
+	if (dev->irq > 0) {
 		irq = dev->irq;
-	else
+		phy->priv.flags |= TPM_TIS_USE_THREADED_IRQ;
+	} else
 		irq = -1;
 
 	init_completion(&phy->ready);
-- 
2.36.0