Re: [PATCH] MdeModulePkg/UfsPassThruDxe: Improve Error handling of Ufs Pass Thru driver

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----Original Message-----
> From: Bandaru, Purna Chandra Rao <purna.chandra.rao.bandaru@intel.com>
> Sent: Wednesday, February 17, 2021 5:02 PM
> To: devel@edk2.groups.io
> Cc: Bandaru, Purna Chandra Rao <purna.chandra.rao.bandaru@intel.com>;
> Albecki, Mateusz <mateusz.albecki@intel.com>; Ni, Ray <ray.ni@intel.com>;
> Wu, Hao A <hao.a.wu@intel.com>
> Subject: [PATCH] MdeModulePkg/UfsPassThruDxe: Improve Error handling
> of Ufs Pass Thru driver
> 
> From: Bandaru <purna.chandra.rao.bandaru@intel.com>
> 
> https://bugzilla.tianocore.org/show_bug.cgi?id=3217
> 
> Following is the brief description of the changes
>  1) There are cards that can take upto 600ms for Init and hence increase
>     the time out for fDeviceInit polling loop.
>  2) Add UFS host conctroller reset in the last retry of Link start up.
>  3) Retry sending NOP OUT command upto 10 times


Hello Bandaru,

Could you help to break this patch into a 3-patch series in V2?
With each patch handling just one of the above 3 improvements mentioned.

For improvement 2) above, I do not see such UFS host controller re-enabling process being mentioned in UFSHCI 3.0 spec section 7.1.1.
Is this process being documented somewhere else in the spec or suggested by device vender?

More inline comments below:


> 
> Signed-off-by: Bandaru <purna.chandra.rao.bandaru@intel.com>
> Cc: Mateusz Albecki <mateusz.albecki@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> 
> Change-Id: I6c0dbc1c147487e51f0ed5f2425957ae089b0160
> ---
>  MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThru.c    | 26
> +++++++++++++++++++++-----
>  MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThruHci.c | 18
> ++++++++++++------
>  2 files changed, 33 insertions(+), 11 deletions(-)
> 
> diff --git a/MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThru.c
> b/MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThru.c
> index 9768c2e6fb..89048745be 100644
> --- a/MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThru.c
> +++ b/MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThru.c
> @@ -1,6 +1,6 @@
>  /** @file
> 
> -  Copyright (c) 2014 - 2019, Intel Corporation. All rights reserved.<BR>
> +  Copyright (c) 2014 - 2021, Intel Corporation. All rights
> + reserved.<BR>
>    Copyright (c) Microsoft Corporation.<BR>
>    SPDX-License-Identifier: BSD-2-Clause-Patent
> 
> @@ -749,7 +749,7 @@ UfsFinishDeviceInitialization (  {
>    EFI_STATUS  Status;
>    UINT8  DeviceInitStatus;
> -  UINT8  Timeout;
> +  UINT16 Timeout;
> 
>    DeviceInitStatus = 0xFF;
> 
> @@ -761,17 +761,23 @@ UfsFinishDeviceInitialization (
>      return Status;
>    }
> 
> -  Timeout = 5;
> +  Timeout = 6000; //There are cards that can take upto 600ms.


Please help to add a macro in file UfsPassThru.h:
#define UFS_INIT_COMPLETION_TIMEOUT 6000
And use the macro here.

Also a minor comment, could you help to use the below comment format?
//
// There are UFS devices that can take up to 600ms to clear the fDeviceInit flag
//
Timeout = UFS_INIT_COMPLETION_TIMEOUT;


>    do {
> +    MicroSecondDelay (100); //Give 100 us and then start polling.


For the above delay movement, do you observe any side effect for the origin code?
If not, I prefer to leave the origin behavior:
do {
  UfsReadFlag();
  ...
  MicroSecondDelay (1);
} while (...)
since doing so will have the least performance penalty for devices that respond fast.


>      Status = UfsReadFlag (Private, UfsFlagDevInit, &DeviceInitStatus);
>      if (EFI_ERROR (Status)) {
>        return Status;
>      }
> -    MicroSecondDelay (1);
>      Timeout--;
>    } while (DeviceInitStatus != 0 && Timeout != 0);
> 
> +  if (Timeout == 0) {
> +    DEBUG ((DEBUG_ERROR, "UfsFinishDeviceInitialization
> DeviceInitStatus=%x EFI_TIMEOUT \n", DeviceInitStatus));
> +    return EFI_TIMEOUT;
> +  } else {
> +    DEBUG ((DEBUG_INFO, "UfsFinishDeviceInitialization Timeout left=%x
> + EFI_SUCCESS \n", Timeout));
>    return EFI_SUCCESS;


Please help to add two spaces for text alignment in the above line.


> +  }
>  }
> 
>  /**
> @@ -905,9 +911,19 @@ UfsPassThruDriverBindingStart (
>    // At the end of the UFS Interconnect Layer initialization on both host and
> device side,
>    // the host shall send a NOP OUT UPIU to verify that the device UTP Layer is
> ready.
>    //


For the NOP OUT - NOP IN improvement, could you help to provide more information on what is the current issue for some devices?
Is it a timeout happened for:
  Status = UfsWaitMemSet (Private, UFS_HC_UTRLDBR_OFFSET, BIT0 << Slot, 0, UFS_TIMEOUT);
(If so, have you tried increasing the last parameter like '10*UFS_TIMEOUT'?)
Or the case is that NopInUpiu->Resp has a non-zero value?

I found that in the UFS 3.0 spec:
|> For some implementations, the device UTP layer may not be initialized yet,
|> therefore the device may not respond promptly to NOP OUT UPIU sending NOP IN
|> UPIU.
|> The host waits until it receives the NOP IN UPIU from the device...
And there is no mention for the retry scheme.


> +  for (Index = 10; Index > 0; Index--) {
>    Status = UfsExecNopCmds (Private);
>    if (EFI_ERROR (Status)) {
> -    DEBUG ((DEBUG_ERROR, "Ufs Sending NOP IN command Error, Status
> = %r\n", Status));
> +      DEBUG ((DEBUG_ERROR, "Ufs Sending NOP IN command Error, Index
> = %x Status = %r\n", Index, Status));
> +      MicroSecondDelay (100); //100 us
> +      continue;
> +    } else {
> +      DEBUG ((DEBUG_INFO, "Ufs Sent NOP OUT successfully and received
> NOP IN, Status = %r\n", Status));
> +      break;
> +    }
> +  }
> +  if (!Index) {
> +    DEBUG ((DEBUG_INFO, "NOP OUT failed all the 10 times Status =
> + %r\n", Status));
>      goto Error;
>    }
> 
> diff --git a/MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThruHci.c
> b/MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThruHci.c
> index 0b1030ab47..4fa5689196 100644
> --- a/MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThruHci.c
> +++ b/MdeModulePkg/Bus/Ufs/UfsPassThruDxe/UfsPassThruHci.c
> @@ -2,7 +2,7 @@
>    UfsPassThruDxe driver is used to produce EFI_EXT_SCSI_PASS_THRU
> protocol interface
>    for upper layer application to execute UFS-supported SCSI cmds.
> 
> -  Copyright (c) 2014 - 2019, Intel Corporation. All rights reserved.<BR>
> +  Copyright (c) 2014 - 2021, Intel Corporation. All rights
> + reserved.<BR>
>    Copyright (c) Microsoft Corporation.<BR>
>    SPDX-License-Identifier: BSD-2-Clause-Patent
> 
> @@ -1929,17 +1929,15 @@ UfsDeviceDetection (
> 
>    //
>    // Start UFS device detection.
> -  // Try up to 3 times for establishing data link with device.
> +  // Try up to 4 times for establishing data link with device.
>    //
> -  for (Retry = 0; Retry < 3; Retry++) {
> +  for (Retry = 0; Retry < 4; Retry++) {


Please introduce a macro in file UfsPassThru.h:
#define UFS_LINK_STARTUP_RETRIES  4
And use the macro here.

Also, is it necessary to increase the retry number by 1?
Or the device can be successfully brought up by adding a host controller re-enabling?


>      LinkStartupCommand.Opcode = UfsUicDmeLinkStartup;
>      LinkStartupCommand.Arg1 = 0;
>      LinkStartupCommand.Arg2 = 0;
>      LinkStartupCommand.Arg3 = 0;
>      Status = UfsExecUicCommands (Private, &LinkStartupCommand);
> -    if (EFI_ERROR (Status)) {
> -      return EFI_DEVICE_ERROR;
> -    }


Will the DME_LINKSTARTUP command execution fail at first and then succeed after retry?
If not, I prefer to keep the origin code logic to return error status directly.


> +    if (!EFI_ERROR (Status)) {
> 
>      Status = UfsMmioRead32 (Private, UFS_HC_STATUS_OFFSET, &Data);
>      if (EFI_ERROR (Status)) {
> @@ -1960,6 +1958,14 @@ UfsDeviceDetection (
>          }
>        }
>        return EFI_SUCCESS;
> +      }
> +    }
> +    if (Retry == 2) {


Please help to update to:
  if (Retry == UFS_LINK_STARTUP_RETRIES - 1) {

And add comments like:
//
// Try re-enabling the UFS host controller in the last retry attempt 
//


Best Regards,
Hao Wu


> +      Status = UfsEnableHostController (Private);
> +      if (EFI_ERROR (Status)) {
> +        DEBUG ((DEBUG_ERROR, "UfsDeviceDetection: Enable Host Controller
> Fails, Status = %r\n", Status));
> +        return Status;
> +      }
>      }
>    }
> 
> --
> 2.16.2.windows.1