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drm/radeon: Read the VRAM VBIOS signature with readb()

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igp_read_bios_from_vram() checked bios[0]/bios[1] with a plain
__iomem load, which faults on sparc64 before the copy runs at all.
radeon_read_bios() already reads its two signature bytes with
readb() ahead of its own copy; use the same accessor here, keeping
the check before the allocation.

Fixes: b442962a9e ("drm/radeon/kms: add support for "Surround View"")
Signed-off-by: Imre Kaloz <kaloz@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 09155b8932)
Cc: stable@vger.kernel.org
This commit is contained in:
Imre Kaloz 2026-09-27 16:55:04 +02:00 committed by Alex Deucher
parent 217f64f348
commit de1eab13ef
1 changed files with 5 additions and 1 deletions
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6
drivers/gpu/drm/radeon/radeon_bios.c
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@ -49,6 +49,7 @@
static bool igp_read_bios_from_vram(struct radeon_device *rdev)
{
uint8_t __iomem *bios;
uint8_t val1, val2;
resource_size_t vram_base;
resource_size_t size = 256 * 1024; /* ??? */
@ -63,7 +64,10 @@ static bool igp_read_bios_from_vram(struct radeon_device *rdev)
return false;
}
if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
val1 = readb(&bios[0]);
val2 = readb(&bios[1]);
if (size == 0 || val1 != 0x55 || val2 != 0xaa) {
iounmap(bios);
return false;
}