Just realized that the patch I pasted won't work. Outer loop exit needs to be
like this.
(reg & MP1_C2PMSG_90__CONTENT_MASK) != 0 && extended_wait-- >= 0
Anyway, that patch is only there to communicate what I really meant in the
earlier comment.
Thanks,
Lijo
-----Original Message-----
From: amd-gfx <[email protected]> On Behalf Of Lazar, Lijo
Sent: Wednesday, December 1, 2021 10:44 AM
To: Yu, Lang <[email protected]>; [email protected]
Cc: Deucher, Alexander <[email protected]>; Huang, Ray
<[email protected]>; Koenig, Christian <[email protected]>
Subject: Re: [PATCH] drm/amdgpu: add SMU debug option support
On 11/30/2021 10:47 AM, Lang Yu wrote:
> To maintain system error state when SMU errors occurred, which will
> aid in debugging SMU firmware issues, add SMU debug option support.
>
> It can be enabled or disabled via amdgpu_smu_debug debugfs file. When
> enabled, it makes SMU errors fatal.
> It is disabled by default.
>
> == Command Guide ==
>
> 1, enable SMU debug option
>
> # echo 1 > /sys/kernel/debug/dri/0/amdgpu_smu_debug
>
> 2, disable SMU debug option
>
> # echo 0 > /sys/kernel/debug/dri/0/amdgpu_smu_debug
>
> v2:
> - Resend command when timeout.(Lijo)
> - Use debugfs file instead of module parameter.
>
> Signed-off-by: Lang Yu <[email protected]>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 32 +++++++++++++++++
> drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 39 +++++++++++++++++++--
> 2 files changed, 69 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> index 164d6a9e9fbb..f9412de86599 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> @@ -39,6 +39,8 @@
>
> #if defined(CONFIG_DEBUG_FS)
>
> +extern int amdgpu_smu_debug;
> +
> /**
> * amdgpu_debugfs_process_reg_op - Handle MMIO register reads/writes
> *
> @@ -1152,6 +1154,8 @@ static ssize_t amdgpu_debugfs_gfxoff_read(struct file
> *f, char __user *buf,
> return result;
> }
>
> +
> +
> static const struct file_operations amdgpu_debugfs_regs2_fops = {
> .owner = THIS_MODULE,
> .unlocked_ioctl = amdgpu_debugfs_regs2_ioctl, @@ -1609,6 +1613,26
> @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_ib_preempt, NULL,
> DEFINE_DEBUGFS_ATTRIBUTE(fops_sclk_set, NULL,
> amdgpu_debugfs_sclk_set, "%llu\n");
>
> +static int amdgpu_debugfs_smu_debug_get(void *data, u64 *val) {
> + *val = amdgpu_smu_debug;
> + return 0;
> +}
> +
> +static int amdgpu_debugfs_smu_debug_set(void *data, u64 val) {
> + if (val != 0 && val != 1)
> + return -EINVAL;
> +
> + amdgpu_smu_debug = val;
> + return 0;
> +}
> +
> +DEFINE_DEBUGFS_ATTRIBUTE(fops_smu_debug,
> + amdgpu_debugfs_smu_debug_get,
> + amdgpu_debugfs_smu_debug_set,
> + "%llu\n");
> +
> int amdgpu_debugfs_init(struct amdgpu_device *adev)
> {
> struct dentry *root = adev_to_drm(adev)->primary->debugfs_root;
> @@ -1632,6 +1656,14 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev)
> return PTR_ERR(ent);
> }
>
> + ent = debugfs_create_file("amdgpu_smu_debug", 0600, root, adev,
> + &fops_smu_debug);
> + if (IS_ERR(ent)) {
> + DRM_ERROR("unable to create amdgpu_smu_debug debugsfs file\n");
> + return PTR_ERR(ent);
> + }
> +
> +
> /* Register debugfs entries for amdgpu_ttm */
> amdgpu_ttm_debugfs_init(adev);
> amdgpu_debugfs_pm_init(adev);
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> index 048ca1673863..b3969d7933d3 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> @@ -55,6 +55,14 @@
>
> #undef __SMU_DUMMY_MAP
> #define __SMU_DUMMY_MAP(type) #type
> +
> +/*
> + * Used to enable SMU debug option. When enabled, it makes SMU errors fatal.
> + * This will aid in debugging SMU firmware issues.
> + * (0 = disabled (default), 1 = enabled) */ int amdgpu_smu_debug;
> +
> static const char * const __smu_message_names[] = {
> SMU_MESSAGE_TYPES
> };
> @@ -272,6 +280,11 @@ int smu_cmn_send_msg_without_waiting(struct smu_context
> *smu,
> __smu_cmn_send_msg(smu, msg_index, param);
> res = 0;
> Out:
> + if (unlikely(amdgpu_smu_debug == 1) && res) {
> + mutex_unlock(&smu->message_lock);
> + BUG();
> + }
> +
> return res;
> }
>
> @@ -288,9 +301,17 @@ int smu_cmn_send_msg_without_waiting(struct smu_context
> *smu,
> int smu_cmn_wait_for_response(struct smu_context *smu)
> {
> u32 reg;
> + int res;
>
> reg = __smu_cmn_poll_stat(smu);
> - return __smu_cmn_reg2errno(smu, reg);
> + res = __smu_cmn_reg2errno(smu, reg);
> +
> + if (unlikely(amdgpu_smu_debug == 1) && res) {
> + mutex_unlock(&smu->message_lock);
> + BUG();
> + }
> +
> + return res;
> }
>
> /**
> @@ -328,6 +349,7 @@ int smu_cmn_send_smc_msg_with_param(struct smu_context
> *smu,
> uint32_t param,
> uint32_t *read_arg)
> {
> + int retry_count = 0;
> int res, index;
> u32 reg;
>
> @@ -349,15 +371,28 @@ int smu_cmn_send_smc_msg_with_param(struct smu_context
> *smu,
> __smu_cmn_reg_print_error(smu, reg, index, param, msg);
> goto Out;
> }
> +retry:
> __smu_cmn_send_msg(smu, (uint16_t) index, param);
> reg = __smu_cmn_poll_stat(smu);
> res = __smu_cmn_reg2errno(smu, reg);
> - if (res != 0)
> + if (res != 0) {
> __smu_cmn_reg_print_error(smu, reg, index, param, msg);
> + if ((res == -ETIME) && (retry_count++ < 1)) {
> + usleep_range(500, 1000);
> + dev_err(smu->adev->dev,
> + "SMU: resend command: index:%d param:0x%08X
> message:%s",
> + index, param, smu_get_message_name(smu, msg));
> + goto retry;
> + }
> + goto Out;
> + }
Sorry, what I meant is to have an extended wait time in debug mode.
Something like below, not a 'full retry' as in sending the message again.
+#define MAX_DBG_WAIT_CNT 3
+
/**
* __smu_cmn_poll_stat -- poll for a status from the SMU
* smu: a pointer to SMU context
@@ -115,17 +117,24 @@ static void smu_cmn_read_arg(struct smu_context *smu,
static u32 __smu_cmn_poll_stat(struct smu_context *smu)
{
struct amdgpu_device *adev = smu->adev;
- int timeout = adev->usec_timeout * 20;
+ int timeout;
u32 reg;
+ int extended_wait = smu_debug_mode ? MAX_DBG_WAIT_CNT : 0;
- for ( ; timeout > 0; timeout--) {
- reg = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90);
- if ((reg & MP1_C2PMSG_90__CONTENT_MASK) != 0)
- break;
+ do {
+ timeout = adev->usec_timeout * 20;
+ for (; timeout > 0; timeout--) {
+ reg = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90);
+ if ((reg & MP1_C2PMSG_90__CONTENT_MASK) != 0)
+ break;
- udelay(1);
- }
+ udelay(1);
+ }
+ } while (extended_wait-- >= 0);
+ if (extended_wait != MAX_DBG_WAIT_CNT && reg != SMU_RESP_NONE)
+ dev_err(adev->dev,
+ "SMU: Unexpected extended wait for response");
return reg;
}
Thanks,
Lijo
> if (read_arg)
> smu_cmn_read_arg(smu, read_arg);
> Out:
> mutex_unlock(&smu->message_lock);
> +
> + BUG_ON(unlikely(amdgpu_smu_debug == 1) && res);
> +
> return res;
> }
>
>
