Commit bd56c63c authored by Chris Wilson's avatar Chris Wilson Committed by Ramalingam C
Browse files

drm/i915: Test all device memory on probing 



This extends the previous sanitychecking of device memory to read/write
all the memory on the device during the device probe, ala memtest86,
as an optional module parameter: i915.memtest=1. This is not expected to
be fast, but a reasonably thorough verfification that the device memory
is accessible and doesn't return bit errors.

v2: Rebased.

Suggested-by: default avatarMatthew Auld <matthew.auld@intel.com>
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: default avatarRamalingam C <ramalingam.c@intel.com>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211208153404.27546-4-ramalingam.c@intel.com
parent 2e21de90

drivers/gpu/drm/i915/i915_params.c

+3 −0
Original line number Diff line number Diff line
@@ -140,6 +140,9 @@ i915_param_named_unsafe(invert_brightness, int, 0400, 
i915_param_named(disable_display, bool, 0400,

	"Disable display (default: false)");



i915_param_named(memtest, bool, 0400,

	"Perform a read/write test of all device memory on module load (default: off)");



i915_param_named(mmio_debug, int, 0400,

	"Enable the MMIO debug code for the first N failures (default: off). "

	"This may negatively affect performance.");

drivers/gpu/drm/i915/i915_params.h

+1 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ struct drm_printer; 
	param(char *, guc_firmware_path, NULL, 0400) \

	param(char *, huc_firmware_path, NULL, 0400) \

	param(char *, dmc_firmware_path, NULL, 0400) \

	param(bool, memtest, false, 0400) \

	param(int, mmio_debug, -IS_ENABLED(CONFIG_DRM_I915_DEBUG_MMIO), 0600) \

	param(int, edp_vswing, 0, 0400) \

	param(unsigned int, reset, 3, 0600) \

drivers/gpu/drm/i915/intel_memory_region.c

+24 −12
Original line number Diff line number Diff line
@@ -93,9 +93,12 @@ static resource_size_t random_page(resource_size_t last) 
	return prandom_u32_max(last >> PAGE_SHIFT) << PAGE_SHIFT;

}



static int iomemtest(struct intel_memory_region *mem, const void *caller)

static int iomemtest(struct intel_memory_region *mem,

		     bool test_all,

		     const void *caller)

{

	resource_size_t last = resource_size(&mem->region) - PAGE_SIZE;

	resource_size_t page;

	int err;



	/*
@@ -109,6 +112,13 @@ static int iomemtest(struct intel_memory_region *mem, const void *caller) 
	 * a random offset within as a quick spot check for bad memory.

	 */



	if (test_all) {

		for (page = 0; page <= last; page += PAGE_SIZE) {

			err = iopagetest(mem, page, caller);

			if (err)

				return err;

		}

	} else {

		err = iopagetest(mem, 0, caller);

		if (err)

			return err;
@@ -120,6 +130,7 @@ static int iomemtest(struct intel_memory_region *mem, const void *caller) 
		err = iopagetest(mem, random_page(last), caller);

		if (err)

			return err;

	}



	return 0;

}
@@ -188,13 +199,14 @@ void intel_memory_region_debug(struct intel_memory_region *mr, 
static int intel_memory_region_memtest(struct intel_memory_region *mem,

				       void *caller)

{

	struct drm_i915_private *i915 = mem->i915;

	int err = 0;



	if (!mem->io_start)

		return 0;



	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))

		err = iomemtest(mem, caller);

	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) || i915->params.memtest)

		err = iomemtest(mem, i915->params.memtest, caller);



	return err;

}