From patchwork Fri Dec 8 21:04:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sam Edwards X-Patchwork-Id: 752015 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="VB8vo0Xq" Received: from mail-il1-x130.google.com (mail-il1-x130.google.com [IPv6:2607:f8b0:4864:20::130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA00E1985; Fri, 8 Dec 2023 13:05:15 -0800 (PST) Received: by mail-il1-x130.google.com with SMTP id e9e14a558f8ab-35d396ae91fso9016175ab.3; Fri, 08 Dec 2023 13:05:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1702069515; x=1702674315; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=QqvWOUimTI+IzTX35gstFYIO9U9PLoGOpX1jOFzw7Ys=; b=VB8vo0Xqp7swVF76pi+Avk7GpowXCingFV9/UxArKQEyRHEnu7a0vK583YvK8KIc4G 6UcTaX4bpynXTE3LBca85RfMUeY1PhinVgGlOhr2wQQC1TeaXvXNHkOYvrtFIE/QWHt6 ozZzWGV9HP9XTSn4uZY5HoQW5RMYZDs/omv6N4NpOGrzhDHYuyxexEkcmwibdnz8On88 U2RGVqvWUJCu/EEk7MPx3RfmV2y6I2mwDmQHruu4Quu4hSwlR25zxt+b3c2YLe6grdrJ W0i32/Av3vgTpgEdUvNUMvrlGZwcGk2LFIrPAK/m5mUn6nm/if5HbAkXwzSz0ne/kGwG 0iWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702069515; x=1702674315; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=QqvWOUimTI+IzTX35gstFYIO9U9PLoGOpX1jOFzw7Ys=; b=jnjbuA4TVP8fwtXfor1XH65CXAj7buihoiIBJ5XGYz2TW/C2T1G3dIEbANQrryu/YT oFcdHNMr5cGGDz4E5JlMzlCt1MGnpveYE5PyFFbTUxGucI1oX+OyihADMcklpcugTAkJ L03sUwckaJFk8ge9XqbLkMn2nXhfmtoKuxoL3DEUws1geQ+FdFUiVJyOc6fPEA4FjZGD uo7bfYFzvWd6e+nh28OZ1B2kL+pKIsdoO6+mA22z+yC1XXp0WW9kZVERBwgo085Scpf0 VaiTLbApKllRfN7sMv7CPDET3XYLQ14cKEgUt2YKRKaJSKj05Zq7cq8SLG5lhKXLu63E UczA== X-Gm-Message-State: AOJu0Yzqxb8b+4HMHkwDyU3Bfef5hiqRT+sduRWUysMHW7zdpDJkBspQ 76MGQP91/PI3d6ndphYAuRk= X-Google-Smtp-Source: AGHT+IHJccm62cOKUWkw44apCwQUzTR5ks7nbDr2UPv/+vNBT8nqq4QoUUazVrDhRPx34NpezSVCGQ== X-Received: by 2002:a05:6e02:1bc9:b0:35d:5f9d:d9be with SMTP id x9-20020a056e021bc900b0035d5f9dd9bemr915380ilv.10.1702069514926; Fri, 08 Dec 2023 13:05:14 -0800 (PST) Received: from celestia.nettie.lan ([2001:470:42c4:101:971d:15c7:de39:3b4b]) by smtp.gmail.com with ESMTPSA id g12-20020a056e020d0c00b0035d5a1760c1sm736458ilj.69.2023.12.08.13.05.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Dec 2023 13:05:14 -0800 (PST) From: Sam Edwards X-Google-Original-From: Sam Edwards To: Mathias Nyman , Thinh Nguyen Cc: Greg Kroah-Hartman , Heiko Stuebner , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Sam Edwards Subject: [PATCH 2/2] usb: dwc3: host: Disable USB3 ports if maximum-speed doesn't permit USB3 Date: Fri, 8 Dec 2023 14:04:58 -0700 Message-ID: <20231208210458.912776-3-CFSworks@gmail.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231208210458.912776-1-CFSworks@gmail.com> References: <20231208210458.912776-1-CFSworks@gmail.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The DWC3 core can be configured (during IP instantiation, and/or via configuration signals) not to have any USB3 ports. Some SoCs, however, may have USB3 interfaces enabled that do not have USB3 PHYs driving them. This can be due to a few circumstances, including: a) The hardware designer didn't include USB3 PHYs and neglected to disable the DWC3 core's USB ports (I know of no instance where this has actually happened, however, and it seems pretty unlikely). b) The USB3 PHYs are present but powered off. Perhaps a driver to enable the PHYs has not yet been written or merged, or USB3 capability is unneeded in the system and the system designer would like to conserve power. c) The USB3 PHYs are muxed to a different controller. This can happen if the PHYs support non-USB protocols and one of these alternate functions is needed instead. In these circumstances, if the DWC3 does not receive clear link status indication on an enabled USB3 port, the DWC3 may not allow even USB2 to function: in host mode, the DWC3 generates an endless barrage of PORT_CSC status on the accompanying USB2 port, and the xHCI driver is unable to bring the USB2 port to a functioning state. Fix this by first checking if the maximum-speed property in the DT permits USB3. If not, pass the new `disable-usb3;` property to the virtual xHCI device, causing the xHCI driver not to enable the USB3 ports. This allows USB2 to function even with USB3 PHYs missing/misbehaving, and may be useful even when the USB3 PHYs are well-behaved: a DT author may know that USB3 support is intact, but disconnected (not exposed off-board) and choose to lower the maximum-speed property to avoid an unusable USB3 rhub showing up in sysfs/lsusb where it may mislead end-users. Signed-off-by: Sam Edwards --- drivers/usb/dwc3/host.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c index 61f57fe5bb78..29f170927e70 100644 --- a/drivers/usb/dwc3/host.c +++ b/drivers/usb/dwc3/host.c @@ -61,7 +61,7 @@ static int dwc3_host_get_irq(struct dwc3 *dwc) int dwc3_host_init(struct dwc3 *dwc) { - struct property_entry props[4]; + struct property_entry props[5]; struct platform_device *xhci; int ret, irq; int prop_idx = 0; @@ -95,6 +95,9 @@ int dwc3_host_init(struct dwc3 *dwc) if (dwc->usb2_lpm_disable) props[prop_idx++] = PROPERTY_ENTRY_BOOL("usb2-lpm-disable"); + if (dwc->maximum_speed == USB_SPEED_FULL || dwc->maximum_speed == USB_SPEED_HIGH) + props[prop_idx++] = PROPERTY_ENTRY_BOOL("disable-usb3"); + /** * WORKAROUND: dwc3 revisions <=3.00a have a limitation * where Port Disable command doesn't work.