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Message-ID: <63a650a449b9937f95f5f2b47546e07e60c06630.camel@gmail.com>
Date: Mon, 17 Jul 2023 16:37:47 +0200
From: Jakub Vaněk <linuxtardis@...il.com>
To: Thinh Nguyen <Thinh.Nguyen@...opsys.com>
Cc: "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"stable@...r.kernel.org" <stable@...r.kernel.org>,
Mauro Ribeiro <mauro.ribeiro@...dkernel.com>,
Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Subject: Re: [PATCH v3] Revert "usb: dwc3: core: Enable AutoRetry feature in
the controller"
Hi Thinh,
On Fri, 2023-07-14 at 21:38 +0000, Thinh Nguyen wrote:
> On Fri, Jul 14, 2023, Jakub Vanek wrote:
> > This reverts commit b138e23d3dff90c0494925b4c1874227b81bddf7.
> >
> > AutoRetry has been found to sometimes cause controller freezes when
> > communicating with buggy USB devices.
> >
> > This controller feature allows the controller in host mode to send
> > non-terminating/burst retry ACKs instead of terminating retry ACKs
> > to devices when a transaction error (CRC error or overflow) occurs.
> >
> > Unfortunately, if the USB device continues to respond with a CRC
> > error,
> > the controller will not complete endpoint-related commands while it
> > keeps trying to auto-retry. [3] The xHCI driver will notice this
> > once
> > it tries to abort the transfer using a Stop Endpoint command and
> > does not receive a completion in time. [1]
> > This situation is reported to dmesg:
> >
> > [sda] tag#29 uas_eh_abort_handler 0 uas-tag 1 inflight: CMD IN
> > [sda] tag#29 CDB: opcode=0x28 28 00 00 69 42 80 00 00 48 00
> > xhci-hcd: xHCI host not responding to stop endpoint command
> > xhci-hcd: xHCI host controller not responding, assume dead
> > xhci-hcd: HC died; cleaning up
> >
> > Some users observed this problem on an Odroid HC2 with the JMS578
> > USB3-to-SATA bridge. The issue can be triggered by starting
> > a read-heavy workload on an attached SSD. After a while, the host
> > controller would die and the SSD would disappear from the system.
> > [1]
> >
> > Further analysis by Synopsys determined that controller revisions
> > other than the one in Odroid HC2 are also affected by this.
> > The recommended solution was to disable AutoRetry altogether.
> > This change does not have a noticeable performance impact. [2]
> >
> > Revert the enablement commit. This will keep the AutoRetry bit in
> > the default state configured during SoC design [2].
> >
> > Fixes: b138e23d3dff ("usb: dwc3: core: Enable AutoRetry feature in
> > the controller")
> > Link:
> > https://urldefense.com/v3/__https://lore.kernel.org/r/a21f34c04632d250cd0a78c7c6f4a1c9c7a43142.camel@gmail.com/__;!!A4F2R9G_pg!cQZmUozSCVry9wEn5TTVGljEo6B_nKIel0kWXsUQbaleJZwkOyrvc4FzWTlbfcUJ7hGz9V50rn0A2WMEceULIS9y9A$
> > [1]
> > Link:
> > https://urldefense.com/v3/__https://lore.kernel.org/r/20230711214834.kyr6ulync32d4ktk@synopsys.com/__;!!A4F2R9G_pg!cQZmUozSCVry9wEn5TTVGljEo6B_nKIel0kWXsUQbaleJZwkOyrvc4FzWTlbfcUJ7hGz9V50rn0A2WMEceXrbrG9iA$
> > [2]
> > Link:
> > https://urldefense.com/v3/__https://lore.kernel.org/r/20230712225518.2smu7wse6djc7l5o@synopsys.com/__;!!A4F2R9G_pg!cQZmUozSCVry9wEn5TTVGljEo6B_nKIel0kWXsUQbaleJZwkOyrvc4FzWTlbfcUJ7hGz9V50rn0A2WMEceWVJz8nuQ$
> > [3]
> > Cc: stable@...r.kernel.org
> > Cc: Mauro Ribeiro <mauro.ribeiro@...dkernel.com>
> > Cc: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
> > Suggested-by: Thinh Nguyen <Thinh.Nguyen@...opsys.com>
> > Signed-off-by: Jakub Vanek <linuxtardis@...il.com>
> > ---
> > V2 -> V3: Include more findings in changelog
> > V1 -> V2: Updated to disable AutoRetry everywhere based on Synopsys
> > feedback
> > Reworded the changelog a bit to make it clearer
> >
> > drivers/usb/dwc3/core.c | 16 ----------------
> > drivers/usb/dwc3/core.h | 3 ---
> > 2 files changed, 19 deletions(-)
> >
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index f6689b731718..a4e079d37566 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -1209,22 +1209,6 @@ static int dwc3_core_init(struct dwc3 *dwc)
> > dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
> > }
> >
> > - if (dwc->dr_mode == USB_DR_MODE_HOST ||
> > - dwc->dr_mode == USB_DR_MODE_OTG) {
> > - reg = dwc3_readl(dwc->regs, DWC3_GUCTL);
> > -
> > - /*
> > - * Enable Auto retry Feature to make the controller
> > operating in
> > - * Host mode on seeing transaction errors(CRC
> > errors or internal
> > - * overrun scenerios) on IN transfers to reply to
> > the device
> > - * with a non-terminating retry ACK (i.e, an ACK
> > transcation
> > - * packet with Retry=1 & Nump != 0)
> > - */
> > - reg |= DWC3_GUCTL_HSTINAUTORETRY;
> > -
> > - dwc3_writel(dwc->regs, DWC3_GUCTL, reg);
> > - }
> > -
> > /*
> > * Must config both number of packets and max burst
> > settings to enable
> > * RX and/or TX threshold.
> > diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> > index 8b1295e4dcdd..a69ac67d89fe 100644
> > --- a/drivers/usb/dwc3/core.h
> > +++ b/drivers/usb/dwc3/core.h
> > @@ -256,9 +256,6 @@
> > #define DWC3_GCTL_GBLHIBERNATIONEN BIT(1)
> > #define DWC3_GCTL_DSBLCLKGTNG BIT(0)
> >
> > -/* Global User Control Register */
> > -#define DWC3_GUCTL_HSTINAUTORETRY BIT(14)
> > -
> > /* Global User Control 1 Register */
> > #define DWC3_GUCTL1_DEV_DECOUPLE_L1L2_EVT BIT(31)
> > #define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS BIT(28)
> > --
> > 2.25.1
> >
>
> Acked-by: Thinh Nguyen <Thinh.Nguyen@...opsys.com>
Thank you!
> Thanks,
> Thinh
Best regards,
Jakub
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