On Tue, Sep 10, 2024 at 11:03:30AM GMT, Rodrigo Vivi wrote:
On Mon, Sep 09, 2024 at 09:33:17AM +0530, Bommu Krishnaiah wrote:
This update addresses the unload/reload sequence of MEI modules in relation to
the i915/Xe graphics driver. On platforms where the MEI hardware is integrated
with the graphics device (e.g., DG2/BMG), the i915/xe driver is depend on the MEI
modules. Conversely, on newer platforms like MTL and LNL, where the MEI hardware
is separate, this dependency does not exist.
The changes introduced ensure that MEI modules are unloaded and reloaded in the
correct order based on platform-specific dependencies. This is achieved by adding
a MODULE_SOFTDEP directive to the i915 and Xe module code.
can you explain what causes the modules to be loaded today? Also, is
this to fix anything related to *loading* order or just unload?
These changes enhance the robustness of MEI module handling across different hardware
platforms, ensuring that the i915/Xe driver can be cleanly unloaded and reloaded
without issues.
v2: updated commit message
Signed-off-by: Bommu Krishnaiah <krishnaiah.bommu@xxxxxxxxx>
Cc: Kamil Konieczny <kamil.konieczny@xxxxxxxxxxxxxxx>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Cc: Tejas Upadhyay <tejas.upadhyay@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_module.c | 2 ++
drivers/gpu/drm/xe/xe_module.c | 2 ++
2 files changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_module.c b/drivers/gpu/drm/i915/i915_module.c
index 65acd7bf75d0..2ad079ad35db 100644
--- a/drivers/gpu/drm/i915/i915_module.c
+++ b/drivers/gpu/drm/i915/i915_module.c
@@ -75,6 +75,8 @@ static const struct {
};
static int init_progress;
+MODULE_SOFTDEP("pre: mei_gsc_proxy mei_gsc");
+
static int __init i915_init(void)
{
int err, i;
diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
index bfc3deebdaa2..5633ea1841b7 100644
--- a/drivers/gpu/drm/xe/xe_module.c
+++ b/drivers/gpu/drm/xe/xe_module.c
@@ -127,6 +127,8 @@ static void xe_call_exit_func(unsigned int i)
init_funcs[i].exit();
}
+MODULE_SOFTDEP("pre: mei_gsc_proxy mei_gsc");
I'm honestly not very comfortable with this.
1. This is not true for every device supported by these modules.
2. This is not true for every (and the most basic) functionality of these drivers.
Shouldn't this be done in the the mei side?
I don't think it's possible to do from the mei side. Would mei depend on
both xe and i915 (and thus cause both to be loaded regardless of the
platform?). For a runtime dependency like this that depends on the
platform, I think the best way would be a weakdep + either a request_module()
or something else that causes the module to load (is that what comp_* is
doing today?)
Couldn't at probe we identify the need of them and if needed we return -EPROBE to
attempt a retry after the mei drivers were probed?
I'm not sure this is fixing anything for probe. I think we already wait on
the other component to be ready without blocking the rest of the driver
functionality.
A weakdep wouldn't cause the module to be loaded where it's not needed,
but need some clarification if this is trying to fix anything
load-related or just unload.
Lucas De Marchi
Cc: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
Cc: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Cc: Alan Previn <alan.previn.teres.alexis@xxxxxxxxx>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tursulin@xxxxxxxxxxx>
+
static int __init xe_init(void)
{
int err, i;
--
2.25.1
