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From: Jarkko Nikula <jarkko.nikula@linux.intel.com>
To: linux-i3c@lists.infradead.org
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Shyam Sundar S K <Shyam-sundar.S-k@amd.com>,
	Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>,
	Krishnamoorthi M <krishnamoorthi.m@amd.com>,
	Jarkko Nikula <jarkko.nikula@linux.intel.com>
Subject: [PATCH 1/2] i3c: mipi-i3c-hci: Mask ring interrupts before ring stop request
Date: Fri, 20 Sep 2024 17:44:31 +0300	[thread overview]
Message-ID: <20240920144432.62370-2-jarkko.nikula@linux.intel.com> (raw)
In-Reply-To: <20240920144432.62370-1-jarkko.nikula@linux.intel.com>

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>
---
 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 a918e96b21fd..13adc5840094 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,
-- 
2.45.2


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  reply	other threads:[~2024-09-20 14:44 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-20 14:44 [PATCH 0/2] i3c: mipi-i3c-hci: DMA interrupt fixes Jarkko Nikula
2024-09-20 14:44 ` Jarkko Nikula [this message]
2024-09-20 14:44 ` [PATCH 2/2] i3c: mipi-i3c-hci: Handle interrupts according to current specifications Jarkko Nikula
2024-09-23  7:39 ` [PATCH 0/2] i3c: mipi-i3c-hci: DMA interrupt fixes Shyam Sundar S K
2024-10-31 23:06 ` Alexandre Belloni

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