Re: [PATCH] drm/amdgpu: use native mode for dp aux transfer

From: Alex Deucher
Date: Thu Aug 11 2022 - 09:57:38 EST


On Thu, Aug 11, 2022 at 7:32 AM Zhenneng Li <lizhenneng@xxxxxxxxxx> wrote:
>
> When using amdgpu for e8860, the monitor sometimes haven't any signal,
> and the kernel reports some errors:
> [ 17.317302][ 2] [ T1045] [drm:amdgpu_atombios_dp_link_train [amdgpu]] *ERROR* channel eq failed: 5 tries
> [ 17.326963][ 2] [ T1045] [drm:amdgpu_atombios_dp_link_train [amdgpu]] *ERROR* channel eq failed
> But if I use radeon for e8860, everything are always normal, the reason is
> that radeon use native mode and amdgpu use atombios mode
> when init dp aux, so when I use native mode for amdgpu, everything
> are always normal.
>
> Signed-off-by: Zhenneng Li <lizhenneng@xxxxxxxxxx>
> Change-Id: Ia9a2be3ab03e56b1c8337fdbf713461196fbc58f
> ---
> drivers/gpu/drm/amd/amdgpu/Makefile | 2 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c | 5 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_dp_auxch.c | 273 +++++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 4 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h | 2 +
> drivers/gpu/drm/amd/amdgpu/atombios_dp.c | 5 +-
> 7 files changed, 290 insertions(+), 3 deletions(-)
> create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_dp_auxch.c
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
> index 3e0e2eb7e235..2913cf46f848 100644
> --- a/drivers/gpu/drm/amd/amdgpu/Makefile
> +++ b/drivers/gpu/drm/amd/amdgpu/Makefile
> @@ -58,7 +58,7 @@ amdgpu-y += amdgpu_device.o amdgpu_kms.o \
> amdgpu_vm_sdma.o amdgpu_discovery.o amdgpu_ras_eeprom.o amdgpu_nbio.o \
> amdgpu_umc.o smu_v11_0_i2c.o amdgpu_fru_eeprom.o amdgpu_rap.o \
> amdgpu_fw_attestation.o amdgpu_securedisplay.o \
> - amdgpu_eeprom.o amdgpu_mca.o amdgpu_psp_ta.o amdgpu_lsdma.o
> + amdgpu_eeprom.o amdgpu_mca.o amdgpu_psp_ta.o amdgpu_lsdma.o amdgpu_dp_auxch.o
>
> amdgpu-$(CONFIG_PROC_FS) += amdgpu_fdinfo.o
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 30ce6bb6fa77..15e0288b1997 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -238,6 +238,8 @@ extern int amdgpu_num_kcq;
> #define AMDGPU_VCNFW_LOG_SIZE (32 * 1024)
> extern int amdgpu_vcnfw_log;
>
> +extern int amdgpu_auxch;
> +
> #define AMDGPU_VM_MAX_NUM_CTX 4096
> #define AMDGPU_SG_THRESHOLD (256*1024*1024)
> #define AMDGPU_DEFAULT_GTT_SIZE_MB 3072ULL /* 3GB by default */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
> index 9ba4817a9148..68c8d79e2937 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c
> @@ -49,7 +49,10 @@ static struct amdgpu_i2c_bus_rec amdgpu_atombios_get_bus_rec_for_i2c_gpio(ATOM_G
>
> memset(&i2c, 0, sizeof(struct amdgpu_i2c_bus_rec));
>
> - i2c.mask_clk_reg = le16_to_cpu(gpio->usClkMaskRegisterIndex);
> + if (amdgpu_auxch)
> + i2c.mask_clk_reg = le16_to_cpu(gpio->usClkMaskRegisterIndex) * 4;
> + else
> + i2c.mask_clk_reg = le16_to_cpu(gpio->usClkMaskRegisterIndex);

You can drop this change if you convert your aux code to use dword
aligned register addresses.

> i2c.mask_data_reg = le16_to_cpu(gpio->usDataMaskRegisterIndex);
> i2c.en_clk_reg = le16_to_cpu(gpio->usClkEnRegisterIndex);
> i2c.en_data_reg = le16_to_cpu(gpio->usDataEnRegisterIndex);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dp_auxch.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dp_auxch.c
> new file mode 100644
> index 000000000000..22078f1ca936
> --- /dev/null
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dp_auxch.c
> @@ -0,0 +1,273 @@
> +/*
> + * Copyright 2015 Red Hat Inc.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + *
> + * Authors: Dave Airlie
> + */
> +
> +#include "amdgpu.h"
> +
> +#define AUX_SW_RX_OVERFLOW (1 << 8)
> +#define AUX_SW_RX_HPD_DISCON (1 << 9)
> +#define AUX_SW_RX_PARTIAL_BYTE (1 << 10)
> +#define AUX_SW_NON_AUX_MODE (1 << 11)
> +#define AUX_SW_RX_SYNC_INVALID_L (1 << 17)
> +#define AUX_SW_RX_SYNC_INVALID_H (1 << 18)
> +#define AUX_SW_RX_INVALID_START (1 << 19)
> +#define AUX_SW_RX_RECV_NO_DET (1 << 20)
> +#define AUX_SW_RX_RECV_INVALID_H (1 << 22)
> +#define AUX_SW_RX_RECV_INVALID_V (1 << 23)
> +#define AUX_CONTROL 0x6200
> +#define AUX_HPD_SEL(x) (((x) & 0x7) << 20)
> +#define AUX_EN (1 << 0)
> +#define AUX_LS_READ_EN (1 << 8)
> +#define AUX_SW_CONTROL 0x6204
> +#define AUX_SW_WR_BYTES(x) (((x) & 0x1f) << 16)
> +#define AUX_SW_DATA 0x6218
> +#define AUX_SW_DATA_RW (1 << 0)
> +#define AUX_SW_AUTOINCREMENT_DISABLE (1 << 31)
> +#define AUX_SW_INTERRUPT_CONTROL 0x620c
> +#define AUX_SW_DONE_ACK (1 << 1)
> +#define AUX_SW_GO (1 << 0)
> +#define AUX_SW_STATUS 0x6210
> +#define AUX_SW_DONE (1 << 0)
> +#define AUX_SW_RX_TIMEOUT (1 << 7)
> +#define AUX_SW_DATA_RW (1 << 0)
> +#define AUX_SW_DATA_MASK(x) (((x) & 0xff) << 8)
> +
> +#define AUX_RX_ERROR_FLAGS (AUX_SW_RX_OVERFLOW | \
> + AUX_SW_RX_HPD_DISCON | \
> + AUX_SW_RX_PARTIAL_BYTE | \
> + AUX_SW_NON_AUX_MODE | \
> + AUX_SW_RX_SYNC_INVALID_L | \
> + AUX_SW_RX_SYNC_INVALID_H | \
> + AUX_SW_RX_INVALID_START | \
> + AUX_SW_RX_RECV_NO_DET | \
> + AUX_SW_RX_RECV_INVALID_H | \
> + AUX_SW_RX_RECV_INVALID_V)
> +
> +#define AUX_SW_REPLY_GET_BYTE_COUNT(x) (((x) >> 24) & 0x1f)
> +
> +#define BARE_ADDRESS_SIZE 3

Use the defines in dce_6_0_d.h and dce_6_0_sh_mask.h instead.

> +
> +#define R100_MM_INDEX 0x0000
> +#define R100_MM_DATA 0x0004
> +#define AMDGPU_MIN_MMIO_SIZE 0x10000
> +uint32_t venus_mm_rreg_slow(struct amdgpu_device *adev, uint32_t reg)
> +{
> + unsigned long flags;
> + uint32_t ret;
> +
> + spin_lock_irqsave(&adev->mmio_idx_lock, flags);
> + writel(reg, ((void __iomem *)adev->rmmio) + R100_MM_INDEX);
> + ret = readl(((void __iomem *)adev->rmmio) + R100_MM_DATA);
> + spin_unlock_irqrestore(&adev->mmio_idx_lock, flags);
> + return ret;
> +}
> +void venus_mm_wreg_slow(struct amdgpu_device *adev, uint32_t reg, uint32_t v)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&adev->mmio_idx_lock, flags);
> + writel(reg, ((void __iomem *)adev->rmmio) + R100_MM_INDEX);
> + writel(v, ((void __iomem *)adev->rmmio) + R100_MM_DATA);
> + spin_unlock_irqrestore(&adev->mmio_idx_lock, flags);
> +}
> +static inline uint32_t venus_mm_rreg(struct amdgpu_device *adev, uint32_t reg,
> + bool always_indirect)
> +{
> + /* The mmio size is 64kb at minimum. Allows the if to be optimized out. */
> + if ((reg < adev->rmmio_size || reg < AMDGPU_MIN_MMIO_SIZE) && !always_indirect)
> + return readl(((void __iomem *)adev->rmmio) + reg);
> + else
> + return venus_mm_rreg_slow(adev, reg);
> +}
> +static inline void venus_mm_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v,
> + bool always_indirect)
> +{
> + if ((reg < adev->rmmio_size || reg < AMDGPU_MIN_MMIO_SIZE) && !always_indirect)
> + writel(v, ((void __iomem *)adev->rmmio) + reg);
> + else
> + venus_mm_wreg_slow(adev, reg, v);
> +}
> +
> +#define RREG32_VENUS(reg) venus_mm_rreg(adev, (reg), false)
> +#define WREG32_VENUS(reg, v) venus_mm_wreg(adev, (reg), (v), false)
> +

drop all of these functions above and just use the existing amdgpu
WREG32/RREG32 macros.

> +static const u32 aux_offset[] =
> +{
> + 0x6200 - 0x6200,
> + 0x6250 - 0x6200,
> + 0x62a0 - 0x6200,
> + 0x6300 - 0x6200,
> + 0x6350 - 0x6200,
> + 0x63a0 - 0x6200,
> +};
> +

convert these to use the macros in dce_6_0_d.h, E.g.,
mmDP_AUX0_AUX_CONTROL - mmDP_AUX0_AUX_CONTROL,
mmDP_AUX1_AUX_CONTROL - mmDP_AUX0_AUX_CONTROL,
etc.

> +ssize_t
> +amdgpu_dp_aux_transfer_native(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
> +{
> + struct amdgpu_i2c_chan *chan =
> + container_of(aux, struct amdgpu_i2c_chan, aux);
> + struct drm_device *dev = chan->dev;
> + struct amdgpu_device *adev = dev->dev_private;
> + int ret = 0, i;
> + uint32_t tmp, ack = 0;
> + int instance = chan->rec.i2c_id & 0xf;
> + u8 byte;
> + u8 *buf = msg->buffer;
> + int retry_count = 0;
> + int bytes;
> + int msize;
> + bool is_write = false;
> +
> + if (WARN_ON(msg->size > 16))
> + return -E2BIG;
> +
> + switch (msg->request & ~DP_AUX_I2C_MOT) {
> + case DP_AUX_NATIVE_WRITE:
> + case DP_AUX_I2C_WRITE:
> + is_write = true;
> + break;
> + case DP_AUX_NATIVE_READ:
> + case DP_AUX_I2C_READ:
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + /* work out two sizes required */
> + msize = 0;
> + bytes = BARE_ADDRESS_SIZE;
> + if (msg->size) {
> + msize = msg->size - 1;
> + bytes++;
> + if (is_write)
> + bytes += msg->size;
> + }
> +
> + mutex_lock(&chan->mutex);
> +
> + /* switch the pad to aux mode */
> + tmp = RREG32_VENUS(chan->rec.mask_clk_reg);
> + tmp |= (1 << 16);
> + WREG32_VENUS(chan->rec.mask_clk_reg, tmp);
> +
> + /* setup AUX control register with correct HPD pin */
> + tmp = RREG32_VENUS(AUX_CONTROL + aux_offset[instance]);
> + tmp &= AUX_HPD_SEL(0x7);
> + tmp |= AUX_HPD_SEL(chan->rec.hpd);
> + tmp |= AUX_EN | AUX_LS_READ_EN;
> +
> + WREG32_VENUS(AUX_CONTROL + aux_offset[instance], tmp);
> +
> + /* atombios appears to write this twice lets copy it */
> + WREG32_VENUS(AUX_SW_CONTROL + aux_offset[instance],
> + AUX_SW_WR_BYTES(bytes));
> + WREG32_VENUS(AUX_SW_CONTROL + aux_offset[instance],
> + AUX_SW_WR_BYTES(bytes));
> +
> + /* write the data header into the registers */
> + /* request, address, msg size */
> + byte = (msg->request << 4) | ((msg->address >> 16) & 0xf);
> + WREG32_VENUS(AUX_SW_DATA + aux_offset[instance],
> + AUX_SW_DATA_MASK(byte) | AUX_SW_AUTOINCREMENT_DISABLE);
> +
> + byte = (msg->address >> 8) & 0xff;
> + WREG32_VENUS(AUX_SW_DATA + aux_offset[instance],
> + AUX_SW_DATA_MASK(byte));
> +
> + byte = msg->address & 0xff;
> + WREG32_VENUS(AUX_SW_DATA + aux_offset[instance],
> + AUX_SW_DATA_MASK(byte));
> +
> + byte = msize;
> + WREG32_VENUS(AUX_SW_DATA + aux_offset[instance],
> + AUX_SW_DATA_MASK(byte));
> +
> + /* if we are writing - write the msg buffer */
> + if (is_write) {
> + for (i = 0; i < msg->size; i++) {
> + WREG32_VENUS(AUX_SW_DATA + aux_offset[instance],
> + AUX_SW_DATA_MASK(buf[i]));
> + }
> + }
> +
> + /* clear the ACK */
> + WREG32_VENUS(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
> +
> + /* write the size and GO bits */
> + WREG32_VENUS(AUX_SW_CONTROL + aux_offset[instance],
> + AUX_SW_WR_BYTES(bytes) | AUX_SW_GO);
> +
> + /* poll the status registers - TODO irq support */
> + do {
> + tmp = RREG32_VENUS(AUX_SW_STATUS + aux_offset[instance]);
> + if (tmp & AUX_SW_DONE) {
> + break;
> + }
> + usleep_range(100, 200);
> + } while (retry_count++ < 1000);
> +
> + if (retry_count >= 1000) {
> + DRM_ERROR("auxch hw never signalled completion, error %08x\n", tmp);
> + ret = -EIO;
> + goto done;
> + }
> +
> + if (tmp & AUX_SW_RX_TIMEOUT) {
> + ret = -ETIMEDOUT;
> + goto done;
> + }
> + if (tmp & AUX_RX_ERROR_FLAGS) {
> + DRM_DEBUG_KMS_RATELIMITED("dp_aux_ch flags not zero: %08x\n",
> + tmp);
> + ret = -EIO;
> + goto done;
> + }
> +
> + bytes = AUX_SW_REPLY_GET_BYTE_COUNT(tmp);
> + if (bytes) {
> + WREG32_VENUS(AUX_SW_DATA + aux_offset[instance],
> + AUX_SW_DATA_RW | AUX_SW_AUTOINCREMENT_DISABLE);
> +
> + tmp = RREG32_VENUS(AUX_SW_DATA + aux_offset[instance]);
> + ack = (tmp >> 8) & 0xff;
> +
> + for (i = 0; i < bytes - 1; i++) {
> + tmp = RREG32_VENUS(AUX_SW_DATA + aux_offset[instance]);
> + if (buf)
> + buf[i] = (tmp >> 8) & 0xff;
> + }
> + if (buf)
> + ret = bytes - 1;
> + }
> +
> + WREG32_VENUS(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
> +
> + if (is_write)
> + ret = msg->size;
> +done:
> + mutex_unlock(&chan->mutex);
> +
> + if (ret >= 0)
> + msg->reply = ack >> 4;
> + return ret;
> +}


This can all move to dce_v6_0.c since it is specific to DCE6.

> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 8890300766a5..2ac7636ddafb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -180,6 +180,7 @@ int amdgpu_num_kcq = -1;
> int amdgpu_smartshift_bias;
> int amdgpu_use_xgmi_p2p = 1;
> int amdgpu_vcnfw_log;
> +int amdgpu_auxch = 0;
>
> static void amdgpu_drv_delayed_reset_work_handler(struct work_struct *work);
>
> @@ -882,6 +883,9 @@ MODULE_PARM_DESC(smu_pptable_id,
> "specify pptable id to be used (-1 = auto(default) value, 0 = use pptable from vbios, > 0 = soft pptable id)");
> module_param_named(smu_pptable_id, amdgpu_smu_pptable_id, int, 0444);
>
> +MODULE_PARM_DESC(auxch, "Use native auxch experimental support (1 = enable, 0 = disable, -1 = auto)");
> +module_param_named(auxch, amdgpu_auxch, int, 0444);
> +
> /* These devices are not supported by amdgpu.
> * They are supported by the mach64, r128, radeon drivers
> */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> index f80b4838cea1..95fffc110c75 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> @@ -619,5 +619,7 @@ int amdgpu_display_crtc_page_flip_target(struct drm_crtc *crtc,
> uint32_t page_flip_flags, uint32_t target,
> struct drm_modeset_acquire_ctx *ctx);
> extern const struct drm_mode_config_funcs amdgpu_mode_funcs;
> +extern ssize_t
> +amdgpu_dp_aux_transfer_native(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg);
>
> #endif
> diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
> index 87c41e0e9b7c..846ecc315665 100644
> --- a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
> +++ b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
> @@ -188,7 +188,10 @@ amdgpu_atombios_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *m
> void amdgpu_atombios_dp_aux_init(struct amdgpu_connector *amdgpu_connector)
> {
> amdgpu_connector->ddc_bus->rec.hpd = amdgpu_connector->hpd.hpd;
> - amdgpu_connector->ddc_bus->aux.transfer = amdgpu_atombios_dp_aux_transfer;
> + if (amdgpu_auxch)
> + amdgpu_connector->ddc_bus->aux.transfer = amdgpu_dp_aux_transfer_native;
> + else
> + amdgpu_connector->ddc_bus->aux.transfer = amdgpu_atombios_dp_aux_transfer;

To make the abstraction cleaner, I would add a callback to the dce
code and then use that to determine which method to use. E.g.,
something like:

if (amdgpu_auxch && adev->mode_info.aux_transfer_native)
amdgpu_connector->ddc_bus->aux.transfer =
adev->mode_info.aux_transfer_native;
else
amdgpu_connector->ddc_bus->aux.transfer = amdgpu_atombios_dp_aux_transfer;

> amdgpu_connector->ddc_bus->aux.drm_dev = amdgpu_connector->base.dev;
>
> drm_dp_aux_init(&amdgpu_connector->ddc_bus->aux);
> --
> 2.25.1
>
>
> No virus found
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