On Mon, Jul 12, 2021 at 10:56 PM Lazar, Lijo <lijo.lazar@xxxxxxx> wrote:
>
>
>
> On 7/12/2021 9:00 PM, Luben Tuikov wrote:
> > This fixes a bug which if we probe a non-existing
> > I2C device, and the SMU returns 0xFF, from then on
> > we can never communicate with the SMU, because the
> > code before this patch reads and interprets 0xFF
> > as a terminal error, and thus we never write 0
> > into register 90 to clear the status (and
> > subsequently send a new command to the SMU.)
> >
> > It is not an error that the SMU returns status
> > 0xFF. This means that the SMU executed the last
> > command successfully (execution status), but the
> > command result is an error of some sort (execution
> > result), depending on what the command was.
> >
> > When doing a status check of the SMU, before we
> > send a new command, the only status which
> > precludes us from sending a new command is 0--the
> > SMU hasn't finished executing a previous command,
> > and 0xFC--the SMU is busy.
> >
> > This bug was seen as the following line in the
> > kernel log,
> >
> > amdgpu: Msg issuing pre-check failed(0xff) and SMU may be not in the right state!
> >
> > when subsequent SMU commands, not necessarily
> > related to I2C, were sent to the SMU.
> >
> > This patch fixes this bug.
> >
> > Cc: Alex Deucher <Alexander.Deucher@xxxxxxx>
> > Cc: Evan Quan <evan.quan@xxxxxxx>
> > Fixes: fcb1fe9c9e0031 ("drm/amd/powerplay: pre-check the SMU state before issuing message")
> > Signed-off-by: Luben Tuikov <luben.tuikov@xxxxxxx>
> > ---
> > drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 196 +++++++++++++++++++------
> > drivers/gpu/drm/amd/pm/swsmu/smu_cmn.h | 3 +-
> > 2 files changed, 152 insertions(+), 47 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> > index c902fdf322c1be..775eb50a2e49a6 100644
> > --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> > +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> > @@ -55,7 +55,7 @@
> >
> > #undef __SMU_DUMMY_MAP
> > #define __SMU_DUMMY_MAP(type) #type
> > -static const char* __smu_message_names[] = {
> > +static const char * const __smu_message_names[] = {
> > SMU_MESSAGE_TYPES
> > };
> >
> > @@ -76,46 +76,161 @@ static void smu_cmn_read_arg(struct smu_context *smu,
> > *arg = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_82);
> > }
> >
> > -int smu_cmn_wait_for_response(struct smu_context *smu)
> > +/**
> > + * __smu_cmn_poll_stat -- poll for a status from the SMU
> > + * smu: a pointer to SMU context
> > + *
> > + * Returns the status of the SMU, which could be,
> > + * 0, the SMU is busy with your previous command;
> > + * 1, execution status: success, execution result: success;
> > + * 0xFF, execution status: success, execution result: failure;
> > + * 0xFE, unknown command;
> > + * 0xFD, valid command, but bad (command) prerequisites;
> > + * 0xFC, the command was rejected as the SMU is busy;
> > + * 0xFB, "SMC_Result_DebugDataDumpEnd".
> > + */
>
> These are the response codes defined in header (0xFB is somehow missing)
> // SMU Response Codes:
> #define PPSMC_Result_OK 0x1
> #define PPSMC_Result_Failed 0xFF
> #define PPSMC_Result_UnknownCmd 0xFE
> #define PPSMC_Result_CmdRejectedPrereq 0xFD
> #define PPSMC_Result_CmdRejectedBusy 0xFC
>
> It's better to use #defines for these, usually we follow a convention
> like SMU_
We could do a MAP_RESULT() macro like we do with the messages, etc. to
make them per asic, but that may be overkill as I think these result
codes have been the same across asics for a long time.
Alex
>
> Ex:
> #define SMU_RESP_RESULT_OK 0x1
>
>
> > +static u32 __smu_cmn_poll_stat(struct smu_context *smu)
> > {
> > struct amdgpu_device *adev = smu->adev;
> > - uint32_t cur_value, i, timeout = adev->usec_timeout * 20;
> > + int timeout = adev->usec_timeout * 20;
> > + u32 reg;
> >
> > - for (i = 0; i < timeout; i++) {
> > - cur_value = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90);
> > - if ((cur_value & MP1_C2PMSG_90__CONTENT_MASK) != 0)
> > - return cur_value;
> > + for ( ; timeout > 0; timeout--) {
> > + reg = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90);
> > + if ((reg & MP1_C2PMSG_90__CONTENT_MASK) != 0)
> > + break;
> >
> > udelay(1);
> > }
> >
> > - /* timeout means wrong logic */
> > - if (i == timeout)
> > - return -ETIME;
> > -
> > - return RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90);
> > + return reg;
> > }
> >
> > -int smu_cmn_send_msg_without_waiting(struct smu_context *smu,
> > - uint16_t msg, uint32_t param)
> > +static void __smu_cmn_reg_print_error(struct smu_context *smu,
> > + u32 reg_c2pmsg_90,
>
> Instead of using reg/regname in function, it would be better to name it
> as smu_cmn_resp/smu_resp or similar to make it clear that we are
> decoding smu response.
>
> > + int msg_index,
> > + u32 param,
> > + enum smu_message_type msg)
> > {
> > struct amdgpu_device *adev = smu->adev;
> > - int ret;
> > + const char *message = smu_get_message_name(smu, msg);
> >
> > - ret = smu_cmn_wait_for_response(smu);
> > - if (ret != 0x1) {
> > - dev_err(adev->dev, "Msg issuing pre-check failed(0x%x) and "
> > - "SMU may be not in the right state!\n", ret);
> > - if (ret != -ETIME)
> > - ret = -EIO;
> > - return ret;
> > + switch (reg_c2pmsg_90) {
> > + case 0:
> > + dev_err_ratelimited(adev->dev,
> > + "SMU: I'm not done with your previous command!");
> > + break;
> > + case 1:
> > + /* The SMU executed the command. It completed with a
> > + * successful result.
> > + */
> > + break;
> > + case 0xFF:
> > + /* The SMU executed the command. It completed with a
> > + * unsuccessful result.
> > + */
> > + break;
> > + case 0xFE:
> > + dev_err_ratelimited(adev->dev,
> > + "SMU: unknown command: index:%d param:0x%08X message:%s",
> > + msg_index, param, message);
> > + break;
> > + case 0xFD:
> > + dev_err_ratelimited(adev->dev,
> > + "SMU: valid command, bad prerequisites: index:%d param:0x%08X message:%s",
> > + msg_index, param, message);
> > + break;
> > + case 0xFC:
> > + dev_err_ratelimited(adev->dev,
> > + "SMU: I'm very busy for your command: index:%d param:0x%08X message:%s",
> > + msg_index, param, message);
> > + break;
> > + case 0xFB:
> > + dev_err_ratelimited(adev->dev,
> > + "SMU: I'm debugging!");
> > + break;
> > + default:
> > + dev_err_ratelimited(adev->dev,
> > + "SMU: response:0x%08X for index:%d param:0x%08X message:%s?",
> > + reg_c2pmsg_90, msg_index, param, message);
> > + break;
> > + }
> > +}
> > +
> > +static int __smu_cmn_reg2errno(struct smu_context *smu, u32 reg_c2pmsg_90)
>
> Same comment on naming - resp2errno?
> > +{
> > + int res;
> > +
> > + switch (reg_c2pmsg_90) {
> > + case 0:
> > + res = -ETIME;
> > + break;
> > + case 1:
> > + res = 0;
> > + break;
> > + case 0xFF:
> > + res = -EIO;
> > + break;
> > + case 0xFE:
> > + res = -EOPNOTSUPP;
> > + break;
> > + case 0xFD:
> > + res = -EIO;
> > + break;
> > + case 0xFC:
> > + res = -EBUSY;
> > + break;
> > + case 0xFB:
> > + res = -EIO;
> > + break;
> > + default:
> > + res = -EIO;
> > + break;
> > }
> >
> > + return res;
> > +}
> > +
> > +static void __smu_cmn_send_msg(struct smu_context *smu,
> > + u16 msg,
> > + u32 param)
> > +{
> > + struct amdgpu_device *adev = smu->adev;
> > +
> > WREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90, 0);
> > WREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_82, param);
> > WREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_66, msg);
> > +}
> >
> > - return 0;
> > +int smu_cmn_send_msg_without_waiting(struct smu_context *smu,
> > + uint16_t msg_index,
> > + uint32_t param)
> > +{
> > + u32 reg;
> > + int res;
> > +
> > + if (smu->adev->in_pci_err_recovery)
> > + return 0;
> > +
> > + mutex_lock(&smu->message_lock);
> > + reg = __smu_cmn_poll_stat(smu);
> > + if (reg == 0 || reg == 0xFC) {
>
> The problem with 0xFC check is it could be the response of a previous
> message. It could mean that FW was busy when the prev message was sent,
> not now.
>
> There is a default case (value not in any of the predefined error
> codes), that should be considered here also. That happens sometimes and
> usually that means FW is in undefined state.
>
>
> > + res = __smu_cmn_reg2errno(smu, reg);
> > + goto Out;
>
> Label naming style, lower case?.
>
> > + }
> > + __smu_cmn_send_msg(smu, msg_index, param);
> > + res = 0;
> > +Out:
> > + mutex_unlock(&smu->message_lock);
> > + return res;
> > +}
> > +
> > +int smu_cmn_wait_for_response(struct smu_context *smu)
> > +{
> > + u32 reg;
> > +
> > + reg = __smu_cmn_poll_stat(smu);
> > + return __smu_cmn_reg2errno(smu, reg);
> > }
> >
> > int smu_cmn_send_smc_msg_with_param(struct smu_context *smu,
> > @@ -123,8 +238,8 @@ int smu_cmn_send_smc_msg_with_param(struct smu_context *smu,
> > uint32_t param,
> > uint32_t *read_arg)
> > {
> > - struct amdgpu_device *adev = smu->adev;
> > - int ret = 0, index = 0;
> > + int res, index;
> > + u32 reg;
> >
> > if (smu->adev->in_pci_err_recovery)
> > return 0;
> > @@ -136,31 +251,20 @@ int smu_cmn_send_smc_msg_with_param(struct smu_context *smu,
> > return index == -EACCES ? 0 : index;
> >
> > mutex_lock(&smu->message_lock);
> > - ret = smu_cmn_send_msg_without_waiting(smu, (uint16_t)index, param);
> > - if (ret)
> > - goto out;
> > -
> > - ret = smu_cmn_wait_for_response(smu);
> > - if (ret != 0x1) {
> > - if (ret == -ETIME) {
> > - dev_err(adev->dev, "message: %15s (%d) \tparam: 0x%08x is timeout (no response)\n",
> > - smu_get_message_name(smu, msg), index, param);
> > - } else {
> > - dev_err(adev->dev, "failed send message: %15s (%d) \tparam: 0x%08x response %#x\n",
> > - smu_get_message_name(smu, msg), index, param,
> > - ret);
> > - ret = -EIO;
> > - }
> > - goto out;
> > + reg = __smu_cmn_poll_stat(smu);
> > + if (reg == 0 || reg == 0xFC) {
>
> Same comments as for without_waiting case.
>
> > + res = __smu_cmn_reg2errno(smu, reg);
> > + __smu_cmn_reg_print_error(smu, reg, index, param, msg);
>
> This precheck fail print is missing in without_waiting message.
>
> > + goto Out; > }
> > -
> > + __smu_cmn_send_msg(smu, (uint16_t) index, param);
> > + reg = __smu_cmn_poll_stat(smu);
> > + res = __smu_cmn_reg2errno(smu, reg);
>
> Using smu_cmn_wait_for_response instead of these two makes the intent
> clearer - that we are waiting for the response.
>
> We need a print here as well if the message has failed.
>
> Thanks,
> Lijo
>
> > if (read_arg)
> > smu_cmn_read_arg(smu, read_arg);
> > -
> > - ret = 0; /* 0 as driver return value */
> > -out:
> > +Out:
> > mutex_unlock(&smu->message_lock);
> > - return ret;
> > + return res;
> > }
> >
> > int smu_cmn_send_smc_msg(struct smu_context *smu,
> > diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.h b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.h
> > index 9add5f16ff562a..16993daa2ae042 100644
> > --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.h
> > +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.h
> > @@ -27,7 +27,8 @@
> >
> > #if defined(SWSMU_CODE_LAYER_L2) || defined(SWSMU_CODE_LAYER_L3) || defined(SWSMU_CODE_LAYER_L4)
> > int smu_cmn_send_msg_without_waiting(struct smu_context *smu,
> > - uint16_t msg, uint32_t param);
> > + uint16_t msg_index,
> > + uint32_t param);
> > int smu_cmn_send_smc_msg_with_param(struct smu_context *smu,
> > enum smu_message_type msg,
> > uint32_t param,
> >
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
_______________________________________________
amd-gfx mailing list
amd-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
