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thunderbolt: Fix connection issue with Pluggable UD-4VPD dock

PATCH Superseded Mika Westerberg 2 participants 6 messages Nov 5, 2024

Subsystems (3)

v1 of 2 Superseded Latest is v2 →

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#0 lore raw

PATCH 1/1 thunderbolt: Fix connection issue with Pluggable UD-4VPD dock

Rick reported that his Pluggable USB4 dock does not work anymore after 6.6.28 kernel.

It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay") makes the device router enumeration happen later than what might be expected by the dock (although there is no such limit in the USB4 spec) which probably makes it assume there is something wrong with the high-speed link and reset it. After the link is reset the same issue happens again and again.

For this reason lower the sideband access delay from 5ms to 1ms. This seems to work fine according to Rick's testing.

Fixes c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")
---
 drivers/thunderbolt/usb4.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/thunderbolt/usb4.c +1 -1
index 0a9b4aeb3fa1..402fdf8b1cde 100644
@@ -48,7 +48,7 @@ enum usb4_ba_index {
 
 /* Delays in us used with usb4_port_wait_for_bit() */
 #define USB4_PORT_DELAY			50
-#define USB4_PORT_SB_DELAY		5000
+#define USB4_PORT_SB_DELAY		1000
 
 static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
 				 u32 *metadata, u8 *status,
Signature · 1 line
2.45.2
maintainer
#1 lore raw
Quoted 10 lines · Mika Westerberg

Rick reported that his Pluggable USB4 dock does not work anymore after 6.6.28 kernel.

It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay") makes the device router enumeration happen later than what might be expected by the dock (although there is no such limit in the USB4 spec) which probably makes it assume there is something wrong with the high-speed link and reset it. After the link is reset the same issue happens again and again.

Quoted 7 lines

For this reason lower the sideband access delay from 5ms to 1ms. This seems to work fine according to Rick's testing.

Fixes c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")

This commit is not in the 6.6.y tree, it only showed up in 6.10.y, so how does this resolve an issue in the 6.6.y tree?

confused,

greg k-h

#2 lore raw

Hi Greg,

Quoted 14 lines · Greg KH
Quoted 13 lines · Mika Westerberg

Rick reported that his Pluggable USB4 dock does not work anymore after 6.6.28 kernel.

It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay") makes the device router enumeration happen later than what might be expected by the dock (although there is no such limit in the USB4 spec) which probably makes it assume there is something wrong with the high-speed link and reset it. After the link is reset the same issue happens again and again.

For this reason lower the sideband access delay from 5ms to 1ms. This seems to work fine according to Rick's testing.

Quoted 7 lines
Quoted 4 lines
Fixes c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")

This commit is not in the 6.6.y tree, it only showed up in 6.10.y, so how does this resolve an issue in the 6.6.y tree?

This refers to a mainline commit that caused the issue. The 6.6.28 is the kernel version Rick used where it still worked. In other words, this is not a backport of a fix but a fix intented to the mainline ;-) I hope this clarifies. I can adjust the commit message if needed.

maintainer
#3 lore raw
Quoted 22 lines · Mika Westerberg

Hi Greg,

Quoted 19 lines · Greg KH
Quoted 17 lines · Mika Westerberg

Rick reported that his Pluggable USB4 dock does not work anymore after 6.6.28 kernel.

It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay") makes the device router enumeration happen later than what might be expected by the dock (although there is no such limit in the USB4 spec) which probably makes it assume there is something wrong with the high-speed link and reset it. After the link is reset the same issue happens again and again.

For this reason lower the sideband access delay from 5ms to 1ms. This seems to work fine according to Rick's testing.

Fixes c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")
Quoted 7 lines
Quoted 2 lines

This commit is not in the 6.6.y tree, it only showed up in 6.10.y, so how does this resolve an issue in the 6.6.y tree?

This refers to a mainline commit that caused the issue. The 6.6.28 is the kernel version Rick used where it still worked. In other words, this is not a backport of a fix but a fix intented to the mainline ;-) I hope this clarifies. I can adjust the commit message if needed.

Ah, yeah, that is confusing so rewording it might be good as the offending kernel is really 6.10, not 6.6.

Also, do you want me to take this in my tree now when you resend it, or do you want to send it with other changes later?

thanks,

greg k-h

#4 lore raw
Quoted 26 lines · Greg KH
Quoted 25 lines · Mika Westerberg

Hi Greg,

Quoted 21 lines · Greg KH
Quoted 10 lines · Mika Westerberg

Rick reported that his Pluggable USB4 dock does not work anymore after 6.6.28 kernel.

It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay") makes the device router enumeration happen later than what might be expected by the dock (although there is no such limit in the USB4 spec) which probably makes it assume there is something wrong with the high-speed link and reset it. After the link is reset the same issue happens again and again.

Quoted 7 lines

For this reason lower the sideband access delay from 5ms to 1ms. This seems to work fine according to Rick's testing.

Fixes c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")

This commit is not in the 6.6.y tree, it only showed up in 6.10.y, so how does this resolve an issue in the 6.6.y tree?

Quoted 7 lines
Quoted 4 lines

This refers to a mainline commit that caused the issue. The 6.6.28 is the kernel version Rick used where it still worked. In other words, this is not a backport of a fix but a fix intented to the mainline ;-) I hope this clarifies. I can adjust the commit message if needed.

Ah, yeah, that is confusing so rewording it might be good as the offending kernel is really 6.10, not 6.6.

Okay will do!

Quoted 2 lines

Also, do you want me to take this in my tree now when you resend it, or do you want to send it with other changes later?

I'll send it along with one more fix later this week if that's fine.

maintainer
#5 lore raw
Quoted 35 lines · Mika Westerberg
Quoted 26 lines · Greg KH
Quoted 25 lines · Mika Westerberg

Hi Greg,

Quoted 21 lines · Greg KH
Quoted 10 lines · Mika Westerberg

Rick reported that his Pluggable USB4 dock does not work anymore after 6.6.28 kernel.

It looks like commit c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay") makes the device router enumeration happen later than what might be expected by the dock (although there is no such limit in the USB4 spec) which probably makes it assume there is something wrong with the high-speed link and reset it. After the link is reset the same issue happens again and again.

Quoted 7 lines

For this reason lower the sideband access delay from 5ms to 1ms. This seems to work fine according to Rick's testing.

Fixes c6ca1ac9f472 ("thunderbolt: Increase sideband access polling delay")

This commit is not in the 6.6.y tree, it only showed up in 6.10.y, so how does this resolve an issue in the 6.6.y tree?

Quoted 7 lines
Quoted 4 lines

This refers to a mainline commit that caused the issue. The 6.6.28 is the kernel version Rick used where it still worked. In other words, this is not a backport of a fix but a fix intented to the mainline ;-) I hope this clarifies. I can adjust the commit message if needed.

Ah, yeah, that is confusing so rewording it might be good as the offending kernel is really 6.10, not 6.6.

Quoted 6 lines

Okay will do!

Quoted 2 lines

Also, do you want me to take this in my tree now when you resend it, or do you want to send it with other changes later?

I'll send it along with one more fix later this week if that's fine.

Sure!