| Message ID | 20230712224037.24948-1-linuxtardis@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] Revert "usb: dwc3: core: Enable AutoRetry feature in the controller" | expand |
On Thu, Jul 13, 2023, Jakub Vaněk wrote: > Hi Thinh, > > On Wed, 2023-07-12 at 22:55 +0000, Thinh Nguyen wrote: > > On Thu, Jul 13, 2023, Jakub Vanek wrote: > > > This reverts commit b138e23d3dff90c0494925b4c1874227b81bddf7. > > > > > > AutoRetry has been found to cause some issues. This feature allows > > > the controller in host mode (further referred to as the xHC) to > > > send > > > non-terminating/burst retry ACKs (Retry=1 and Nump!=0) instead of > > > terminating retry ACKs (Retry=1 and Nump=0) to devices when > > > a transaction error occurs. > > > > > > Unfortunately, some USB devices fail to retry transactions when > > > the xHC sends them a burst retry ACK. When this happens, the xHC > > > > For some clarity: if the device continues to respond with CRC error, > > the xHC will not complete endpoint related commands while it keeps > > autoretry. > > Acknowledged. Do you think it it would be better to respin this patch > once more to include this in the changelog? > It'll be better to provide more detail. However, I'm fine whether you want to send v3 with this or not. Thanks, Thinh
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)
This reverts commit b138e23d3dff90c0494925b4c1874227b81bddf7. AutoRetry has been found to cause some issues. This feature allows the controller in host mode (further referred to as the xHC) to send non-terminating/burst retry ACKs (Retry=1 and Nump!=0) instead of terminating retry ACKs (Retry=1 and Nump=0) to devices when a transaction error occurs. Unfortunately, some USB devices fail to retry transactions when the xHC sends them a burst retry ACK. When this happens, the xHC enters a strange state. After the affected transfer times out, the xHCI driver tries to resume normal operation of the xHC by sending it a Stop Endpoint command. However, the xHC fails to respond to it, and the xHCI driver gives up. [1] This fact is reported via 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] Fixes: b138e23d3dff ("usb: dwc3: core: Enable AutoRetry feature in the controller") Link: https://lore.kernel.org/r/a21f34c04632d250cd0a78c7c6f4a1c9c7a43142.camel@gmail.com/ [1] Link: https://lore.kernel.org/r/20230711214834.kyr6ulync32d4ktk@synopsys.com/ [2] Cc: stable@vger.kernel.org Cc: Mauro Ribeiro <mauro.ribeiro@hardkernel.com> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Suggested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Signed-off-by: Jakub Vanek <linuxtardis@gmail.com> --- 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(-)