[PATCH net-next v2 06/10] net: dsa: realtek: rtl8365mb: store the egress queue count per chip

[Oleksij Rempel]

Store the number of egress queues in the per-chip info structure and
advertise it through ds->num_tx_queues, following the ksz driver
(struct ksz_chip_data.num_tx_queues).

The queue count is a per-chip hardware property, and this driver supports
several chips of the rtl8367c family. All currently supported chips expose
eight queues, but keeping the count in chip_info lets the QoS code that
follows program the priority-to-queue map via the ieee8021q helpers for
whatever queue count a chip carries, so the 802.1Q collapse is correct
rather than hard-coded to eight.

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Reviewed-by: Linus Walleij <linusw@xxxxxxxxxx>
Reviewed-by: Luiz Angelo Daros de Luca <luizluca@xxxxxxxxx>
---
Q: Linus: why is the queue count not in struct realtek_variant?
A: The count is per chip, while realtek_variant is per subdriver, and
rtl8365mb serves several chips. The QoS code added later in this series
reads ds->num_tx_queues, as Linus suggested in his v1 review, so
RTL8366RB can advertise its own count the same way.

Changes in v2:
- drop the num_tx_queues comment, which restated the assignment
- keep the Reviewed-by tags: v2 only drops a comment
---
 drivers/net/dsa/realtek/rtl8365mb_main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/dsa/realtek/rtl8365mb_main.c b/drivers/net/dsa/realtek/rtl8365mb_main.c
index 1e6cdc61f6bd3b3f74e422dbbcfdcb67cc0532a7..f7960d94f1cd9f6a1982849a9e5a1b5d98880b4b 100644
--- a/drivers/net/dsa/realtek/rtl8365mb_main.c
+++ b/drivers/net/dsa/realtek/rtl8365mb_main.c
@@ -711,6 +711,7 @@ struct rtl8365mb_extint {
  * @extints: available external interfaces
  * @jam_table: chip-specific initialization jam table
  * @jam_size: size of the chip's jam table
+ * @num_tx_queues: number of egress queues exposed by the chip
  *
  * These data are specific to a given chip in the family of switches supported
  * by this driver. When adding support for another chip in the family, a new
@@ -724,6 +725,7 @@ struct rtl8365mb_chip_info {
 	const struct rtl8365mb_extint extints[RTL8365MB_MAX_NUM_EXTINTS];
 	const struct rtl8365mb_jam_tbl_entry *jam_table;
 	size_t jam_size;
+	unsigned int num_tx_queues;
 };
 
 /* Chip info for each supported switch in the family */
@@ -748,6 +750,7 @@ static const struct rtl8365mb_chip_info rtl8365mb_chip_infos[] = {
 		},
 		.jam_table = rtl8365mb_init_jam_8365mb_vc,
 		.jam_size = ARRAY_SIZE(rtl8365mb_init_jam_8365mb_vc),
+		.num_tx_queues = 8,
 	},
 	{
 		.name = "RTL8367S",
@@ -761,6 +764,7 @@ static const struct rtl8365mb_chip_info rtl8365mb_chip_infos[] = {
 		},
 		.jam_table = rtl8365mb_init_jam_8365mb_vc,
 		.jam_size = ARRAY_SIZE(rtl8365mb_init_jam_8365mb_vc),
+		.num_tx_queues = 8,
 	},
 	{
 		.name = "RTL8367SB",
@@ -776,6 +780,7 @@ static const struct rtl8365mb_chip_info rtl8365mb_chip_infos[] = {
 		},
 		.jam_table = rtl8365mb_init_jam_8365mb_vc,
 		.jam_size = ARRAY_SIZE(rtl8365mb_init_jam_8365mb_vc),
+		.num_tx_queues = 8,
 	},
 	{
 		.name = "RTL8367RB-VB",
@@ -790,6 +795,7 @@ static const struct rtl8365mb_chip_info rtl8365mb_chip_infos[] = {
 		},
 		.jam_table = rtl8365mb_init_jam_8365mb_vc,
 		.jam_size = ARRAY_SIZE(rtl8365mb_init_jam_8365mb_vc),
+		.num_tx_queues = 8,
 	},
 };
 
@@ -3288,6 +3294,8 @@ static int rtl8365mb_setup(struct dsa_switch *ds)
 		goto out_teardown_irq;
 	}
 
+	ds->num_tx_queues = mb->chip_info->num_tx_queues;
+
 	/* Start statistics counter polling */
 	ret = rtl8365mb_stats_setup(priv);
 	if (ret) {

-- 
2.47.3