[PATCH] i3c: mipi-i3c-hci: Fix number of DAT/DCT entries for HCI versions < 1.1

* [PATCH] i3c: mipi-i3c-hci: Fix number of DAT/DCT entries for HCI versions < 1.1
@ 2024-06-14 14:02 Jarkko Nikula
  2024-06-14 14:14 ` Greg KH
  2024-06-22 22:34 ` Alexandre Belloni
  0 siblings, 2 replies; 4+ messages in thread
From: Jarkko Nikula @ 2024-06-14 14:02 UTC (permalink / raw)
  To: linux-i3c; +Cc: Alexandre Belloni, stable, Jarkko Nikula

I was wrong about the TABLE_SIZE field description in the
commit 0676bfebf576 ("i3c: mipi-i3c-hci: Fix DAT/DCT entry sizes").

For the MIPI I3C HCI versions 1.0 and earlier the TABLE_SIZE field in
the registers DAT_SECTION_OFFSET and DCT_SECTION_OFFSET is indeed defined
in DWORDs and not number of entries like it is defined in later versions.

Where above fix allowed driver initialization to continue the wrongly
interpreted TABLE_SIZE field leads variables DAT_entries being twice and
DCT_entries four times as big as they really are.

That in turn leads clearing the DAT table over the boundary in the
dat_v1.c: hci_dat_v1_init().

So interprete the TABLE_SIZE field in DWORDs for HCI versions < 1.1 and
fix number of DAT/DCT entries accordingly.

Fixes: 0676bfebf576 ("i3c: mipi-i3c-hci: Fix DAT/DCT entry sizes")
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
---
 drivers/i3c/master/mipi-i3c-hci/core.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index faf723a0c739..0ff3055b8e78 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -646,6 +646,7 @@ static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id)
 static int i3c_hci_init(struct i3c_hci *hci)
 {
 	u32 regval, offset;
+	bool size_in_dwords;
 	int ret;
 
 	/* Validate HCI hardware version */
@@ -670,11 +671,16 @@ static int i3c_hci_init(struct i3c_hci *hci)
 	hci->caps = reg_read(HC_CAPABILITIES);
 	DBG("caps = %#x", hci->caps);
 
+	size_in_dwords = hci->version_major < 1 ||
+			 (hci->version_major == 1 && hci->version_minor < 1);
+
 	regval = reg_read(DAT_SECTION);
 	offset = FIELD_GET(DAT_TABLE_OFFSET, regval);
 	hci->DAT_regs = offset ? hci->base_regs + offset : NULL;
 	hci->DAT_entries = FIELD_GET(DAT_TABLE_SIZE, regval);
 	hci->DAT_entry_size = FIELD_GET(DAT_ENTRY_SIZE, regval) ? 0 : 8;
+	if (size_in_dwords)
+		hci->DAT_entries = 4 * hci->DAT_entries / hci->DAT_entry_size;
 	dev_info(&hci->master.dev, "DAT: %u %u-bytes entries at offset %#x\n",
 		 hci->DAT_entries, hci->DAT_entry_size, offset);
 
@@ -683,6 +689,8 @@ static int i3c_hci_init(struct i3c_hci *hci)
 	hci->DCT_regs = offset ? hci->base_regs + offset : NULL;
 	hci->DCT_entries = FIELD_GET(DCT_TABLE_SIZE, regval);
 	hci->DCT_entry_size = FIELD_GET(DCT_ENTRY_SIZE, regval) ? 0 : 16;
+	if (size_in_dwords)
+		hci->DCT_entries = 4 * hci->DCT_entries / hci->DCT_entry_size;
 	dev_info(&hci->master.dev, "DCT: %u %u-bytes entries at offset %#x\n",
 		 hci->DCT_entries, hci->DCT_entry_size, offset);
 
-- 
2.43.0


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