drm/xe/sysctrl: Fix mailbox header handling

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The mailbox header was defined as __le32, which required
cpu_to_le32() and le32_to_cpu() conversions whenever it was
write or read.

These conversions are unnecessary because the header is always
handled as a 32-bit value, not as raw bytes. It is written with
xe_mmio_write32() and read with xe_mmio_read32(), which already
handle any required byte-order conversion through the underlying
writel()/readl() accessors.

As a result, the header value is already in CPU byte order when
used by the driver. Keeping the extra conversions had no effect
on little-endian systems and could cause an incorrect on
big-endian systems.

So use u32 for the mailbox header and remove the unnecessary
endianness conversions.

Fixes: 1f95f61818 ("drm/xe/xe_sysctrl: Add System Controller mailbox communication support")
Suggested-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Mallesh Koujalagi <mallesh.koujalagi@intel.com>
Tested-by: Anoop Vijay <anoop.c.vijay@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patch.msgid.link/20260924060900.146167-18-mallesh.koujalagi@intel.com
(cherry picked from commit 5137b391599579371c32f555958d3cf55e19bd88)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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This commit is contained in:

Mallesh Koujalagi 2026-09-24 11:39:07 +05:30 • committed by Rodrigo Vivi

parent cf238c067e

commit f0a4447789

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drivers/gpu/drm/xe/xe_sysctrl_mailbox.c

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