[PATCH AUTOSEL 6.12 03/15] i3c: mipi-i3c-hci: Mask ring interrupts before ring stop request

Sasha Levin
2024-12-04T17:11:34Z

From: Jarkko Nikula <jarkko.nikula@linux.intel.com>

[ Upstream commit 6ca2738174e4ee44edb2ab2d86ce74f015a0cc32 ]

Bus cleanup path in DMA mode may trigger a RING_OP_STAT interrupt when
the ring is being stopped. Depending on timing between ring stop request
completion, interrupt handler removal and code execution this may lead
to a NULL pointer dereference in hci_dma_irq_handler() if it gets to run
after the io_data pointer is set to NULL in hci_dma_cleanup().

Prevent this my masking the ring interrupts before ring stop request.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20240920144432.62370-2-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index a918e96b21fdd..13adc58400942 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -159,10 +159,10 @@ static void hci_dma_cleanup(struct i3c_hci *hci)
for (i = 0; i < rings->total; i++) {
rh = &rings->headers[i];

+ rh_reg_write(INTR_SIGNAL_ENABLE, 0);
rh_reg_write(RING_CONTROL, 0);
rh_reg_write(CR_SETUP, 0);
rh_reg_write(IBI_SETUP, 0);
- rh_reg_write(INTR_SIGNAL_ENABLE, 0);

if (rh->xfer)
dma_free_coherent(&hci->master.dev,
--
2.43.0