[PATCH v4 12/36] thunderbolt: Properly disable path

Mika Westerberg
2019-04-10T13:42:02Z

We need to wait until all buffers have been drained before the path can
be considered disabled. Do this for every hop in a path.

This adds another bit field to struct tb_regs_hop even if we are trying
to get rid of them but we can clean them up another day.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/thunderbolt/path.c | 47 ++++++++++++++++++++++++++++++++---
drivers/thunderbolt/tb_regs.h | 3 ++-
2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c
index a11956522bac..8c2e19a6117a 100644
--- a/drivers/thunderbolt/path.c
+++ b/drivers/thunderbolt/path.c
@@ -7,6 +7,8 @@

#include <linux/slab.h>
#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/ktime.h>

#include "tb.h"

@@ -74,14 +76,51 @@ static void __tb_path_deallocate_nfc(struct tb_path *path, int first_hop)
}
}

+static int __tb_path_deactivate_hop(struct tb_port *port, int hop_index)
+{
+ struct tb_regs_hop hop;
+ ktime_t timeout;
+ int ret;
+
+ /* Disable the path */
+ ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
+ if (ret)
+ return ret;
+
+ /* Already disabled */
+ if (!hop.enable)
+ return 0;
+
+ hop.enable = 0;
+
+ ret = tb_port_write(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
+ if (ret)
+ return ret;
+
+ /* Wait until it is drained */
+ timeout = ktime_add_ms(ktime_get(), 500);
+ do {
+ ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
+ if (ret)
+ return ret;
+
+ if (!hop.pending)
+ return 0;
+
+ usleep_range(10, 20);
+ } while (ktime_before(ktime_get(), timeout));
+
+ return -ETIMEDOUT;
+}
+
static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop)
{
int i, res;
- struct tb_regs_hop hop = { };
+
for (i = first_hop; i < path->path_length; i++) {
- res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
- 2 * path->hops[i].in_hop_index, 2);
- if (res)
+ res = __tb_path_deactivate_hop(path->hops[i].in_port,
+ path->hops[i].in_hop_index);
+ if (res && res != -ENODEV)
tb_port_warn(path->hops[i].in_port,
"hop deactivation failed for hop %d, index %d\n",
i, path->hops[i].in_hop_index);
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 1ab6e0fb31c0..82ac4ec8757f 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -234,7 +234,8 @@ struct tb_regs_hop {
bool egress_fc:1;
bool ingress_shared_buffer:1;
bool egress_shared_buffer:1;
- u32 unknown3:4; /* set to zero */
+ bool pending:1;
+ u32 unknown3:3; /* set to zero */
} __packed;

/* Common link controller registers */
--
2.20.1