Actually the main difference is not root vs. user, but rather unstable vs stable interface. If you want a stable interface for an userspace tool you should use sysfs, if you don't care about that you should use debugfs. Christian. Am 24.08.2017 um 18:37 schrieb Russell, Kent: > We already access the GPU Power usage via debugfs, which is why I didn't think it was a huge deal to switch it over, since we already need root access for the SMI due to that. > > Kent > > -----Original Message----- > From: Alex Deucher [mailto:alexdeucher at gmail.com] > Sent: Thursday, August 24, 2017 11:39 AM > To: Kuehling, Felix > Cc: Russell, Kent; Christian König; amd-gfx at lists.freedesktop.org > Subject: Re: [PATCH] drm/amdgpu: Add sysfs file for VBIOS > > On Thu, Aug 24, 2017 at 11:35 AM, Kuehling, Felix <Felix.Kuehling at amd.com> wrote: >> Debugfs is only accessible by Root. The BIOS version is already reported in the kernel log, which is visible to everyone. So why hide this away in debugfs? >> >> I think Kent's intention is to add VBIOS version reporting to the rocm-smi tool. I'd prefer using a stable interface like sysfs, and one that doesn't require root access in a tool like rocm-smi. >> > Ah, ok, sysfs is fine in that case. I thought this was just general debugging stuff. > > Alex > >> Regards, >> Felix >> ________________________________________ >> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> on behalf of >> Russell, Kent <Kent.Russell at amd.com> >> Sent: Thursday, August 24, 2017 9:06:22 AM >> To: Alex Deucher >> Cc: Christian König; amd-gfx at lists.freedesktop.org >> Subject: RE: [PATCH] drm/amdgpu: Add sysfs file for VBIOS >> >> I can definitely add that as well. >> >> Kent >> >> -----Original Message----- >> From: Alex Deucher [mailto:alexdeucher at gmail.com] >> Sent: Thursday, August 24, 2017 8:56 AM >> To: Russell, Kent >> Cc: Christian König; amd-gfx at lists.freedesktop.org >> Subject: Re: [PATCH] drm/amdgpu: Add sysfs file for VBIOS >> >> On Thu, Aug 24, 2017 at 5:58 AM, Russell, Kent <Kent.Russell at amd.com> wrote: >>> No real reason for sysfs instead of debugfs, I just picked the one that was more familiar with. I can definitely move it to debugfs instead. I will also clean up the commit message per Michel's comments. Thank you! >>> >> While you are at it, can you expose the vbios binary itself via debugfs? That's been on by todo list for a while. >> >> Alex >> >>> Kent >>> >>> -----Original Message----- >>> From: Christian König [mailto:deathsimple at vodafone.de] >>> Sent: Thursday, August 24, 2017 2:22 AM >>> To: Russell, Kent; amd-gfx at lists.freedesktop.org >>> Subject: Re: [PATCH] drm/amdgpu: Add sysfs file for VBIOS >>> >>> Am 23.08.2017 um 20:12 schrieb Kent Russell: >>>> This won't change after initialization, so we can add the >>>> information when we parse the atombios information. This ensures >>>> that we can find out the VBIOS, even when the dmesg buffer fills up, >>>> and makes it easier to associate which VBIOS is for which GPU on >>>> mGPU configurations. Set the size to 20 characters in case of some >>>> weird VBIOS suffix that exceeds the expected 17 character format >>>> (3-8-3\0) >>> Is there any reason that needs to be sysfs? Sounds more like an use case for debugfs. >>> >>> Christian. >>> >>>> Signed-off-by: Kent Russell <kent.russell at amd.com> >>>> --- >>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 23 +++++++++++++++++++++++ >>>> drivers/gpu/drm/amd/amdgpu/atom.c | 5 ++++- >>>> drivers/gpu/drm/amd/amdgpu/atom.h | 1 + >>>> 3 files changed, 28 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c >>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c >>>> index a1f9424..f40be71 100644 >>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c >>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c >>>> @@ -888,6 +888,20 @@ static uint32_t cail_ioreg_read(struct card_info *info, uint32_t reg) >>>> return r; >>>> } >>>> >>>> +static ssize_t amdgpu_atombios_get_vbios_version(struct device *dev, >>>> + struct device_attribute *attr, >>>> + char *buf) { >>>> + struct drm_device *ddev = dev_get_drvdata(dev); >>>> + struct amdgpu_device *adev = ddev->dev_private; >>>> + struct atom_context *ctx = adev->mode_info.atom_context; >>>> + >>>> + return snprintf(buf, PAGE_SIZE, "%s\n", ctx->vbios_version); } >>>> + >>>> +static DEVICE_ATTR(vbios_version, 0444, amdgpu_atombios_get_vbios_version, >>>> + NULL); >>>> + >>>> /** >>>> * amdgpu_atombios_fini - free the driver info and callbacks for atombios >>>> * >>>> @@ -907,6 +921,7 @@ static void amdgpu_atombios_fini(struct amdgpu_device *adev) >>>> adev->mode_info.atom_context = NULL; >>>> kfree(adev->mode_info.atom_card_info); >>>> adev->mode_info.atom_card_info = NULL; >>>> + device_remove_file(adev->dev, &dev_attr_vbios_version); >>>> } >>>> >>>> /** >>>> @@ -923,6 +938,7 @@ static int amdgpu_atombios_init(struct amdgpu_device *adev) >>>> { >>>> struct card_info *atom_card_info = >>>> kzalloc(sizeof(struct card_info), GFP_KERNEL); >>>> + int ret; >>>> >>>> if (!atom_card_info) >>>> return -ENOMEM; >>>> @@ -959,6 +975,13 @@ static int amdgpu_atombios_init(struct amdgpu_device *adev) >>>> amdgpu_atombios_scratch_regs_init(adev); >>>> amdgpu_atombios_allocate_fb_scratch(adev); >>>> } >>>> + >>>> + ret = device_create_file(adev->dev, &dev_attr_vbios_version); >>>> + if (ret) { >>>> + DRM_ERROR("Failed to create device file for VBIOS version\n"); >>>> + return ret; >>>> + } >>>> + >>>> return 0; >>>> } >>>> >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/atom.c >>>> b/drivers/gpu/drm/amd/amdgpu/atom.c >>>> index d69aa2e..69500a8 100644 >>>> --- a/drivers/gpu/drm/amd/amdgpu/atom.c >>>> +++ b/drivers/gpu/drm/amd/amdgpu/atom.c >>>> @@ -1343,8 +1343,11 @@ struct atom_context *amdgpu_atom_parse(struct card_info *card, void *bios) >>>> idx = 0x80; >>>> >>>> str = CSTR(idx); >>>> - if (*str != '\0') >>>> + if (*str != '\0') { >>>> pr_info("ATOM BIOS: %s\n", str); >>>> + strlcpy(ctx->vbios_version, str, sizeof(ctx->vbios_version)); >>>> + } >>>> + >>>> >>>> return ctx; >>>> } >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/atom.h >>>> b/drivers/gpu/drm/amd/amdgpu/atom.h >>>> index ddd8045..a391709 100644 >>>> --- a/drivers/gpu/drm/amd/amdgpu/atom.h >>>> +++ b/drivers/gpu/drm/amd/amdgpu/atom.h >>>> @@ -140,6 +140,7 @@ struct atom_context { >>>> int io_mode; >>>> uint32_t *scratch; >>>> int scratch_size_bytes; >>>> + char vbios_version[20]; >>>> }; >>>> >>>> extern int amdgpu_atom_debug; >>> >>> _______________________________________________ >>> amd-gfx mailing list >>> amd-gfx at lists.freedesktop.org >>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx >> _______________________________________________ >> amd-gfx mailing list >> amd-gfx at lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx > _______________________________________________ > amd-gfx mailing list > amd-gfx at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx