[v4] thunderbolt: Disable Gen 4 Recovery on Asymmetric Transitions

Message ID	20250131014406.28645-4-rahimi.mhmmd@gmail.com (mailing list archive)
State	New
Headers	show Received: from mail-pj1-f54.google.com (mail-pj1-f54.google.com [209.85.216.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E2A31819; Fri, 31 Jan 2025 01:45:38 +0000 (UTC) From: Mohammad Rahimi <rahimi.mhmmd@gmail.com> To: mika.westerberg@linux.intel.com Cc: andreas.noever@gmail.com, michael.jamet@intel.com, YehezkelShB@gmail.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Mohammad Rahimi <rahimi.mhmmd@gmail.com> Subject: [PATCH v4] thunderbolt: Disable Gen 4 Recovery on Asymmetric Transitions Date: Fri, 31 Jan 2025 01:41:27 +0000 Message-ID: <20250131014406.28645-4-rahimi.mhmmd@gmail.com> In-Reply-To: <20250131014406.28645-1-rahimi.mhmmd@gmail.com> References: <20250131014406.28645-1-rahimi.mhmmd@gmail.com> Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
Series	[v4] thunderbolt: Disable Gen 4 Recovery on Asymmetric Transitions \| expand [v4] thunderbolt: Disable Gen 4 Recovery on Asymmetric Transitions

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c index a7c6919fbf97..a3ccfb398797 100644 --- a/drivers/thunderbolt/tb.c +++ b/drivers/thunderbolt/tb.c @@ -1013,6 +1013,7 @@ static int tb_configure_asym(struct tb *tb, struct tb_port *src_port, struct tb_port *dst_port, int requested_up, int requested_down) { + bool link_recovery_up = false, link_recovery_down = false; bool clx = false, clx_disabled = false, downstream; struct tb_switch *sw; struct tb_port *up; @@ -1075,15 +1076,19 @@ static int tb_configure_asym(struct tb *tb, struct tb_port *src_port, continue; /* - * Disable CL states before doing any transitions. We - * delayed it until now that we know there is a real - * transition taking place. + * Disable CL states and Link Recovery before doing any + * transitions. We delayed it until now that we know + * there is a real transition taking place. */ if (!clx_disabled) { clx = tb_disable_clx(sw); clx_disabled = true; } + /* Ignore non-critical errors of disabling Link Recovery */ + link_recovery_up = (usb4_port_link_recovery_disable(up) > 0); + link_recovery_down = (usb4_port_link_recovery_disable(down) > 0); + tb_sw_dbg(up->sw, "configuring asymmetric link\n"); /* @@ -1091,6 +1096,13 @@ static int tb_configure_asym(struct tb *tb, struct tb_port *src_port, * transtion the link into asymmetric now. */ ret = tb_switch_set_link_width(up->sw, width_up); + + /* Re-enable Link Recovery if they were previously enabled */ + if (link_recovery_up) + usb4_port_link_recovery_enable(up); + if (link_recovery_down) + usb4_port_link_recovery_enable(down); + if (ret) { tb_sw_warn(up->sw, "failed to set link width\n"); break; diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h index ddbf0cd78377..d37d778082fc 100644 --- a/drivers/thunderbolt/tb.h +++ b/drivers/thunderbolt/tb.h @@ -1332,6 +1332,9 @@ int usb4_port_router_online(struct tb_port *port); int usb4_port_enumerate_retimers(struct tb_port *port); bool usb4_port_clx_supported(struct tb_port *port); +int usb4_port_link_recovery_enable(struct tb_port *port); +int usb4_port_link_recovery_disable(struct tb_port *port); + bool usb4_port_asym_supported(struct tb_port *port); int usb4_port_asym_set_link_width(struct tb_port *port, enum tb_link_width width); int usb4_port_asym_start(struct tb_port *port); diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h index 4e43b47f9f11..085139e1a958 100644 --- a/drivers/thunderbolt/tb_regs.h +++ b/drivers/thunderbolt/tb_regs.h @@ -398,6 +398,7 @@ struct tb_regs_port_header { #define PORT_CS_19_WOD BIT(17) #define PORT_CS_19_WOU4 BIT(18) #define PORT_CS_19_START_ASYM BIT(24) +#define PORT_CS_19_ELR BIT(31) /* Display Port adapter registers */ #define ADP_DP_CS_0 0x00 diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c index e51d01671d8e..450e3920f20c 100644 --- a/drivers/thunderbolt/usb4.c +++ b/drivers/thunderbolt/usb4.c @@ -10,6 +10,7 @@ #include <linux/delay.h> #include <linux/ktime.h> #include <linux/units.h> +#include <linux/string_helpers.h> #include "sb_regs.h" #include "tb.h" @@ -1518,6 +1519,82 @@ bool usb4_port_clx_supported(struct tb_port *port) return !!(val & PORT_CS_18_CPS); } +static int __usb4_port_link_recovery_enable(struct tb_port *port, bool enable) +{ + bool was_enable; + int ret; + u32 val; + + if (!port->cap_usb4) + return -EINVAL; + + ret = tb_port_read(port, &val, TB_CFG_PORT, + port->cap_usb4 + PORT_CS_19, 1); + if (ret) + return ret; + + was_enable = !!(val & PORT_CS_19_ELR); + + if (enable) + val |= PORT_CS_19_ELR; + else + val &= ~PORT_CS_19_ELR; + + ret = tb_port_write(port, &val, TB_CFG_PORT, + port->cap_usb4 + PORT_CS_19, 1); + if (ret) + return ret; + + tb_port_dbg(port, "link recovery %s\n", str_enabled_disabled(enable)); + return was_enable ? 1 : 0; +} + +/** + * usb4_port_link_recovery_enable() - Enable the Link Recovery + * @port: USB4 port + * + * Enables the Link Recovery for @port. + * + * Returns: + * * %-EINVAL - Capability not present. + * * %-ENODEV - Switch unplugged. + * * %-ETIMEDOUT - Config space access timed out. + * * %0 - Successfully enabled. + * * %1 - Already enabled. + */ +int usb4_port_link_recovery_enable(struct tb_port *port) +{ + int ret = __usb4_port_link_recovery_enable(port, true); + + if (ret < 0) + tb_port_warn(port, "failed to enable link recovery\n"); + + return ret; +} + +/** + * usb4_port_link_recovery_disable() - Disable the Link Recovery + * @port: USB4 port + * + * Disables the Link Recovery for @port. + * + * Returns: + * * %-EINVAL - Capability not present. + * * %-ENODEV - Switch unplugged. + * * %-ETIMEDOUT - Config space access timed out. + * * %0 - Already disabled. + * * %1 - Successfully disabled. + */ +int usb4_port_link_recovery_disable(struct tb_port *port) +{ + int ret = __usb4_port_link_recovery_enable(port, false); + + if (ret < 0) + tb_port_warn(port, "failed to disable link recovery\n"); + + return ret; +} + /** * usb4_port_asym_supported() - If the port supports asymmetric link * @port: USB4 port

[v4] thunderbolt: Disable Gen 4 Recovery on Asymmetric Transitions

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