linux-kernel - [PATCH AUTOSEL 6.13 7/8] i3c: mipi-i3c-hci: Add Intel specific quirk to ring resuming

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250126164523.963930-7-sashal@kernel.org>
Date: Sun, 26 Jan 2025 11:45:22 -0500
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Jarkko Nikula <jarkko.nikula@...ux.intel.com>,
	Alexandre Belloni <alexandre.belloni@...tlin.com>,
	Sasha Levin <sashal@...nel.org>,
	linux-i3c@...ts.infradead.org
Subject: [PATCH AUTOSEL 6.13 7/8] i3c: mipi-i3c-hci: Add Intel specific quirk to ring resuming

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

[ Upstream commit ccdb2e0e3b00d13df90ac7a0524dd855173f1171 ]

MIPI I3C HCI on Intel hardware requires a quirk where ring needs to stop
and set to run again after resuming the halted controller. This is not
expected from the MIPI I3C HCI specification and is Intel specific.

Add this quirk to generic aborted transfer handling and execute it only
when ring is not in running state after a transfer error and attempted
controller resume. This is the case on Intel hardware.

It is not fully clear to me what is the ring running state in generic
hardware in such case. I would expect if ring is not running, then stop
request is a no-op and run request is either required or does the same
what controller resume would do.

Signed-off-by: Jarkko Nikula <jarkko.nikula@...ux.intel.com>
Link: https://lore.kernel.org/r/20241231115904.620052-1-jarkko.nikula@linux.intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@...tlin.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/i3c/master/mipi-i3c-hci/dma.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index e8e56a8d20573..491dfe70b6600 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -758,9 +758,26 @@ static bool hci_dma_irq_handler(struct i3c_hci *hci)
 			complete(&rh->op_done);
 
 		if (status & INTR_TRANSFER_ABORT) {
+			u32 ring_status;
+
 			dev_notice_ratelimited(&hci->master.dev,
 				"ring %d: Transfer Aborted\n", i);
 			mipi_i3c_hci_resume(hci);
+			ring_status = rh_reg_read(RING_STATUS);
+			if (!(ring_status & RING_STATUS_RUNNING) &&
+			    status & INTR_TRANSFER_COMPLETION &&
+			    status & INTR_TRANSFER_ERR) {
+				/*
+				 * Ring stop followed by run is an Intel
+				 * specific required quirk after resuming the
+				 * halted controller. Do it only when the ring
+				 * is not in running state after a transfer
+				 * error.
+				 */
+				rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE);
+				rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE |
+							   RING_CTRL_RUN_STOP);
+			}
 		}
 		if (status & INTR_WARN_INS_STOP_MODE)
 			dev_warn_ratelimited(&hci->master.dev,
-- 
2.39.5