Commit 649663af authored by Mario Limonciello's avatar Mario Limonciello Committed by Alex Deucher
Browse files

drm/amd: Add documentation for how to flash a dGPU 



The flashing process for dGPUs uses sysfs files in a
non-obvious way, so document it for users.

Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 98d19a6c

Documentation/gpu/amdgpu/flashing.rst

0 → 100644
+33 −0
Original line number Diff line number Diff line 
=======================

 dGPU firmware flashing

=======================



IFWI

----

Flashing the dGPU integrated firmware image (IFWI) is supported by GPUs that

use the PSP to orchestrate the update (Navi3x or newer GPUs).

For supported GPUs, `amdgpu` will export a series of sysfs files that can be

used for the flash process.



The IFWI flash process is:



1. Ensure the IFWI image is intended for the dGPU on the system.

2. "Write" the IFWI image to the sysfs file `psp_vbflash`. This will stage the IFWI in memory.

3. "Read" from the `psp_vbflash` sysfs file to initiate the flash process.

4. Poll the `psp_vbflash_status` sysfs file to determine when the flash process completes.



USB-C PD F/W

------------

On GPUs that support flashing an updated USB-C PD firmware image, the process

is done using the `usbc_pd_fw` sysfs file.



* Reading the file will provide the current firmware version.

* Writing the name of a firmware payload stored in `/lib/firmware/amdgpu` to the sysfs file will initiate the flash process.



The firmware payload stored in `/lib/firmware/amdgpu` can be named any name

as long as it doesn't conflict with other existing binaries that are used by

`amdgpu`.



sysfs files

-----------

.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c

Documentation/gpu/amdgpu/index.rst

+1 −0
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@@ -10,6 +10,7 @@ Next (GCN), Radeon DNA (RDNA), and Compute DNA (CDNA) architectures. 
   module-parameters

   driver-core

   display/index

   flashing

   xgmi

   ras

   thermal

drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c

+16 −0
Original line number Diff line number Diff line
@@ -3570,6 +3570,11 @@ void psp_copy_fw(struct psp_context *psp, uint8_t *start_addr, uint32_t bin_size 
	drm_dev_exit(idx);

}



/**

 * DOC: usbc_pd_fw

 * Reading from this file will retrieve the USB-C PD firmware version. Writing to

 * this file will trigger the update process.

 */

static DEVICE_ATTR(usbc_pd_fw, 0644,

		   psp_usbc_pd_fw_sysfs_read,

		   psp_usbc_pd_fw_sysfs_write);
@@ -3663,6 +3668,11 @@ static ssize_t amdgpu_psp_vbflash_read(struct file *filp, struct kobject *kobj, 
	return 0;

}



/**

 * DOC: psp_vbflash

 * Writing to this file will stage an IFWI for update. Reading from this file

 * will trigger the update process.

 */

static struct bin_attribute psp_vbflash_bin_attr = {

	.attr = {.name = "psp_vbflash", .mode = 0660},

	.size = 0,
@@ -3670,6 +3680,12 @@ static struct bin_attribute psp_vbflash_bin_attr = { 
	.read = amdgpu_psp_vbflash_read,

};



/**

 * DOC: psp_vbflash_status

 * The status of the flash process.

 * 0: IFWI flash not complete.

 * 1: IFWI flash complete.

 */

static ssize_t amdgpu_psp_vbflash_status(struct device *dev,

					 struct device_attribute *attr,

					 char *buf)