From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: linux-usb@vger.kernel.org
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>,
Michael Jamet <michael.jamet@intel.com>,
Lukas Wunner <lukas@wunner.de>,
Andreas Noever <andreas.noever@gmail.com>,
Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: [PATCH 1/2] thunderbolt: Increase sideband access polling delay
Date: Thu, 18 Apr 2024 08:06:21 +0300 [thread overview]
Message-ID: <20240418050623.3157002-1-mika.westerberg@linux.intel.com> (raw)
The USB4 sideband access is slow compared to the high-speed link and the
access timing parameters are tens of milliseconds according the spec. To
avoid too much unnecessary polling for the sideband pass the wait delay
to usb4_port_wait_for_bit() and use larger (5ms) value compared to the
high-speed access.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/thunderbolt/usb4.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 78b06e922fda..de480bf2a53d 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -52,6 +52,10 @@ enum usb4_ba_index {
#define USB4_BA_VALUE_MASK GENMASK(31, 16)
#define USB4_BA_VALUE_SHIFT 16
+/* Delays in us used with usb4_port_wait_for_bit() */
+#define USB4_PORT_DELAY 50
+#define USB4_PORT_SB_DELAY 5000
+
static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
u32 *metadata, u8 *status,
const void *tx_data, size_t tx_dwords,
@@ -1245,7 +1249,7 @@ void usb4_port_unconfigure_xdomain(struct tb_port *port)
}
static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
- u32 value, int timeout_msec)
+ u32 value, int timeout_msec, unsigned long delay_usec)
{
ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
@@ -1260,7 +1264,7 @@ static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
if ((val & bit) == value)
return 0;
- usleep_range(50, 100);
+ fsleep(delay_usec);
} while (ktime_before(ktime_get(), timeout));
return -ETIMEDOUT;
@@ -1308,7 +1312,7 @@ static int usb4_port_sb_read(struct tb_port *port, enum usb4_sb_target target,
return ret;
ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
- PORT_CS_1_PND, 0, 500);
+ PORT_CS_1_PND, 0, 500, USB4_PORT_SB_DELAY);
if (ret)
return ret;
@@ -1355,7 +1359,7 @@ static int usb4_port_sb_write(struct tb_port *port, enum usb4_sb_target target,
return ret;
ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
- PORT_CS_1_PND, 0, 500);
+ PORT_CS_1_PND, 0, 500, USB4_PORT_SB_DELAY);
if (ret)
return ret;
@@ -1410,6 +1414,8 @@ static int usb4_port_sb_op(struct tb_port *port, enum usb4_sb_target target,
if (val != opcode)
return usb4_port_sb_opcode_err_to_errno(val);
+
+ fsleep(USB4_PORT_SB_DELAY);
} while (ktime_before(ktime_get(), timeout));
return -ETIMEDOUT;
@@ -1591,13 +1597,14 @@ int usb4_port_asym_start(struct tb_port *port)
* port started the symmetry transition.
*/
ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_19,
- PORT_CS_19_START_ASYM, 0, 1000);
+ PORT_CS_19_START_ASYM, 0, 1000,
+ USB4_PORT_DELAY);
if (ret)
return ret;
/* Then wait for the transtion to be completed */
return usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_18,
- PORT_CS_18_TIP, 0, 5000);
+ PORT_CS_18_TIP, 0, 5000, USB4_PORT_DELAY);
}
/**
@@ -2123,7 +2130,8 @@ static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
*/
val &= ADP_USB3_CS_2_CMR;
return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
- ADP_USB3_CS_1_HCA, val, 1500);
+ ADP_USB3_CS_1_HCA, val, 1500,
+ USB4_PORT_DELAY);
}
static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
--
2.43.0
next reply other threads:[~2024-04-18 5:06 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-18 5:06 Mika Westerberg [this message]
2024-04-18 5:06 ` [PATCH 2/2] thunderbolt: No need to loop over all retimers if access fails Mika Westerberg
2024-04-23 5:14 ` [PATCH 1/2] thunderbolt: Increase sideband access polling delay Mika Westerberg
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