[PATCH v3 1/3] i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode

[Jian-Ming Liao]

In PIO mode initialization, STAT_IBI_STATUS_THLD was missing from
pio->enabled_irqs. As a result, the host controller interrupt signal for
IBI threshold was never enabled when transfer starts, preventing IBI
status descriptors from being properly processed in PIO mode.

Include STAT_IBI_STATUS_THLD in pio->enabled_irqs so that the IBI
threshold interrupt is activated alongside error interrupts upon the first
transfer.

Fixes: 9ad9a52cce28 ("i3c/master: introduce the mipi-i3c-hci driver")
Co-developed-by: Patrick Yen <Patrick_Yen at asmedia.com.tw>
Signed-off-by: Patrick Yen <Patrick_Yen at asmedia.com.tw>
Signed-off-by: Jian-Ming Liao <Jm_Liao at asmedia.com.tw>
---
v3:
 - Added Fixes tag (Adrian).
 - Updated commit message and code comment to accurately reflect that
   STAT_IBI_STATUS_THLD is activated on the first transfer (Adrian).
 - Aligned From: and Signed-off-by: email addresses (Adrian).
v2:
 - Removed "Hot-Join" references from the commit message and comments,
   as the change focuses strictly on enabling STAT_IBI_STATUS_THLD
   for general IBI reception per HCI spec.
   
 drivers/i3c/master/mipi-i3c-hci/pio.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/pio.c b/drivers/i3c/master/mipi-i3c-hci/pio.c
index ff2657ee220b..a1341d66bc65 100644
--- a/drivers/i3c/master/mipi-i3c-hci/pio.c
+++ b/drivers/i3c/master/mipi-i3c-hci/pio.c
@@ -185,8 +185,11 @@ static void __hci_pio_init(struct i3c_hci *hci, u32 *size_val_ptr)
 	pio_reg_write(INTR_SIGNAL_ENABLE, 0x0);
 	pio_reg_write(INTR_STATUS_ENABLE, 0xffffffff);
 
-	/* Always accept error interrupts (will be activated on first xfer) */
-	pio->enabled_irqs = STAT_ALL_ERRORS;
+	/*
+	 * Always accept error interrupts and IBI threshold interrupt
+	 * (will be activated on first xfer).
+	 */
+	pio->enabled_irqs = STAT_ALL_ERRORS | STAT_IBI_STATUS_THLD;
 }
 
 static void hci_pio_suspend(struct i3c_hci *hci)
-- 
2.43.0