This is a note to let you know that I've just added the patch titled
thunderbolt: Limit USB3 bandwidth of certain Intel USB4 host routers
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
thunderbolt-limit-usb3-bandwidth-of-certain-intel-us.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 37e2a48598a23c799b1dd4fabaa5b7d6bec7ab4c
Author: Gil Fine <gil.fine@xxxxxxxxxxxxxxx>
Date: Tue Jan 31 13:04:52 2023 +0200
thunderbolt: Limit USB3 bandwidth of certain Intel USB4 host routers
[ Upstream commit f0a57dd33b3eadf540912cd130db727ea824d174 ]
Current Intel USB4 host routers have hardware limitation that the USB3
bandwidth cannot go higher than 16376 Mb/s. Work this around by adding a
new quirk that limits the bandwidth for the affected host routers.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Gil Fine <gil.fine@xxxxxxxxxxxxxxx>
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/thunderbolt/quirks.c b/drivers/thunderbolt/quirks.c
index ae28a03fa890b..1157b8869bcca 100644
--- a/drivers/thunderbolt/quirks.c
+++ b/drivers/thunderbolt/quirks.c
@@ -26,6 +26,19 @@ static void quirk_clx_disable(struct tb_switch *sw)
tb_sw_dbg(sw, "disabling CL states\n");
}
+static void quirk_usb3_maximum_bandwidth(struct tb_switch *sw)
+{
+ struct tb_port *port;
+
+ tb_switch_for_each_port(sw, port) {
+ if (!tb_port_is_usb3_down(port))
+ continue;
+ port->max_bw = 16376;
+ tb_port_dbg(port, "USB3 maximum bandwidth limited to %u Mb/s\n",
+ port->max_bw);
+ }
+}
+
struct tb_quirk {
u16 hw_vendor_id;
u16 hw_device_id;
@@ -43,6 +56,24 @@ static const struct tb_quirk tb_quirks[] = {
* DP buffers.
*/
{ 0x8087, 0x0b26, 0x0000, 0x0000, quirk_dp_credit_allocation },
+ /*
+ * Limit the maximum USB3 bandwidth for the following Intel USB4
+ * host routers due to a hardware issue.
+ */
+ { 0x8087, PCI_DEVICE_ID_INTEL_ADL_NHI0, 0x0000, 0x0000,
+ quirk_usb3_maximum_bandwidth },
+ { 0x8087, PCI_DEVICE_ID_INTEL_ADL_NHI1, 0x0000, 0x0000,
+ quirk_usb3_maximum_bandwidth },
+ { 0x8087, PCI_DEVICE_ID_INTEL_RPL_NHI0, 0x0000, 0x0000,
+ quirk_usb3_maximum_bandwidth },
+ { 0x8087, PCI_DEVICE_ID_INTEL_RPL_NHI1, 0x0000, 0x0000,
+ quirk_usb3_maximum_bandwidth },
+ { 0x8087, PCI_DEVICE_ID_INTEL_MTL_M_NHI0, 0x0000, 0x0000,
+ quirk_usb3_maximum_bandwidth },
+ { 0x8087, PCI_DEVICE_ID_INTEL_MTL_P_NHI0, 0x0000, 0x0000,
+ quirk_usb3_maximum_bandwidth },
+ { 0x8087, PCI_DEVICE_ID_INTEL_MTL_P_NHI1, 0x0000, 0x0000,
+ quirk_usb3_maximum_bandwidth },
/*
* CLx is not supported on AMD USB4 Yellow Carp and Pink Sardine platforms.
*/
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index e11d973a8f9b6..f034723b1b40e 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -252,6 +252,8 @@ struct tb_switch {
* @ctl_credits: Buffers reserved for control path
* @dma_credits: Number of credits allocated for DMA tunneling for all
* DMA paths through this port.
+ * @max_bw: Maximum possible bandwidth through this adapter if set to
+ * non-zero.
*
* In USB4 terminology this structure represents an adapter (protocol or
* lane adapter).
@@ -277,6 +279,7 @@ struct tb_port {
unsigned int total_credits;
unsigned int ctl_credits;
unsigned int dma_credits;
+ unsigned int max_bw;
};
/**
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index d5cd219ee9e6b..3a11b30b6c86a 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -1882,6 +1882,15 @@ int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
usb4_port_retimer_nvm_read_block, &info);
}
+static inline unsigned int
+usb4_usb3_port_max_bandwidth(const struct tb_port *port, unsigned int bw)
+{
+ /* Take the possible bandwidth limitation into account */
+ if (port->max_bw)
+ return min(bw, port->max_bw);
+ return bw;
+}
+
/**
* usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
* @port: USB3 adapter port
@@ -1903,7 +1912,9 @@ int usb4_usb3_port_max_link_rate(struct tb_port *port)
return ret;
lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
- return lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
+ ret = lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
+
+ return usb4_usb3_port_max_bandwidth(port, ret);
}
/**
@@ -1930,7 +1941,9 @@ int usb4_usb3_port_actual_link_rate(struct tb_port *port)
return 0;
lr = val & ADP_USB3_CS_4_ALR_MASK;
- return lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
+ ret = lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
+
+ return usb4_usb3_port_max_bandwidth(port, ret);
}
static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
