[PATCH 5.13 106/351] thunderbolt: Fix DROM handling for USB4 DROM

Greg Kroah-Hartman
2021-07-19T17:24:41Z

From: Gil Fine <gil.fine@intel.com>

[ Upstream commit b18f901382fdb74a138a0bf30458c54a023a1d86 ]

DROM for USB4 host/device has a shorter header than Thunderbolt DROM
header. This patch addresses host/device with USB4 DROM (According to spec:
Universal Serial Bus 4 (USB4) Device ROM Specification, Rev 1.0, Feb-2021).

While there correct the data_len field to be 12 bits and rename
__unknown1 to reserved following the spec.

Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/thunderbolt/eeprom.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index 46d0906a3070..470885e6f1c8 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -214,7 +214,10 @@ static u32 tb_crc32(void *data, size_t len)
return ~__crc32c_le(~0, data, len);
}

-#define TB_DROM_DATA_START 13
+#define TB_DROM_DATA_START 13
+#define TB_DROM_HEADER_SIZE 22
+#define USB4_DROM_HEADER_SIZE 16
+
struct tb_drom_header {
/* BYTE 0 */
u8 uid_crc8; /* checksum for uid */
@@ -224,9 +227,9 @@ struct tb_drom_header {
u32 data_crc32; /* checksum for data_len bytes starting at byte 13 */
/* BYTE 13 */
u8 device_rom_revision; /* should be <= 1 */
- u16 data_len:10;
- u8 __unknown1:6;
- /* BYTES 16-21 */
+ u16 data_len:12;
+ u8 reserved:4;
+ /* BYTES 16-21 - Only for TBT DROM, nonexistent in USB4 DROM */
u16 vendor_id;
u16 model_id;
u8 model_rev;
@@ -401,10 +404,10 @@ static int tb_drom_parse_entry_port(struct tb_switch *sw,
*
* Drom must have been copied to sw->drom.
*/
-static int tb_drom_parse_entries(struct tb_switch *sw)
+static int tb_drom_parse_entries(struct tb_switch *sw, size_t header_size)
{
struct tb_drom_header *header = (void *) sw->drom;
- u16 pos = sizeof(*header);
+ u16 pos = header_size;
u16 drom_size = header->data_len + TB_DROM_DATA_START;
int res;

@@ -566,7 +569,7 @@ static int tb_drom_parse(struct tb_switch *sw)
header->data_crc32, crc);
}

- return tb_drom_parse_entries(sw);
+ return tb_drom_parse_entries(sw, TB_DROM_HEADER_SIZE);
}

static int usb4_drom_parse(struct tb_switch *sw)
@@ -583,7 +586,7 @@ static int usb4_drom_parse(struct tb_switch *sw)
return -EINVAL;
}

- return tb_drom_parse_entries(sw);
+ return tb_drom_parse_entries(sw, USB4_DROM_HEADER_SIZE);
}

/**
--
2.30.2