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McKenney" , Matt Fleming , linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, iwata.koki@fujitsu.com Subject: [PATCH RESEND] Documentation: admin-guide: fix a doc for efi_no_storage_paranoia the "5KB" instead of the "50%" Date: Fri, 10 Jul 2026 15:22:44 +0900 Message-ID: <20260710062306.1204206-1-iwata.koki@fujitsu.com> X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Iwata Koki The documentation for 'efi_no_storage_paranoia' incorrectly states the kernel cannot use "more than 50%" of the EFI variable storage. This percentage-based explanation has been outdated since commit f8b8404337de ("Modify UEFI anti-bricking code") introduced a fixed 5KB minimum reserve threshold (EFI_MIN_RESERVE) in arch/x86/platform/efi/quirks.c. At that time, the documentation was not updated to reflect this change. Update the documentation to reflect the "5KB" instead of the "50%". Fixes: f8b8404337de ("Modify UEFI anti-bricking code") Signed-off-by: Koki Iwata --- Documentation/admin-guide/kernel-parameters.txt | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b5493a7f8f22..3f75969a679b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1614,10 +1614,17 @@ Kernel parameters on all PCI bridges while in the EFI boot stub efi_no_storage_paranoia [EFI,X86,EARLY] - Using this parameter you can use more than 50% of - your efi variable storage. Use this parameter only if - you are really sure that your UEFI does sane gc and - fulfills the spec otherwise your board may brick. + The kernel reserves 5KB of EFI variable storage for + safety, because some UEFI implementation may fail to + boot if there's insufficient space in the EFI variable + storage. + + Using this parameter, you can use the 5KB reservation + in the EFI variable storage. + + However, Use this parameter only if you are really + sure that your UEFI does sane gc and fulfills the spec + otherwise your board may brick. efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT that is to be dynamically loaded by Linux. If there are -- 2.52.0