Re: [GIT PULL] x86 fixes

Matt Fleming
2014-09-24T11:42:42Z

On Wed, 24 Sep, at 09:26:33AM, Ingo Molnar wrote:
>
> So 'status' is unused - either use it for a less threatening
> message, or remove the return code from the function and document
> that failure is an option?

I think removing the return code is the way to go (I have a patch queued
for v3.18 that adds call-site error messages).

Something like this?

---

>From 737ed0ea66f79fe1e5343f9f4cbdf7c0f57e1a0f Mon Sep 17 00:00:00 2001
From: Matt Fleming <matt.fleming@intel.com>
Date: Thu, 11 Sep 2014 09:04:25 +0100
Subject: [PATCH] x86/efi: Delete misleading efi_printk() error message
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

A number of people are reporting seeing the "setup_efi_pci() failed!"
error message in what used to be a quiet boot,

https://bugzilla.kernel.org/show_bug.cgi?id=81891

The message isn't all that helpful because setup_efi_pci() can return a
non-success error code for a variety of reasons, not all of them fatal.

Let's drop the return code from setup_efi_pci*() altogether, since
there's no way to process it in any meaningful way outside of the inner
__setup_efi_pci*() functions.

Reported-by: Darren Hart <dvhart@linux.intel.com>
Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Ulf Winkelvos <ulf@winkelvos.de>
Cc: Andre Müller <andre.muller@web.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
---
arch/x86/boot/compressed/eboot.c | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 8c311ab1b8c8..41ded80b3424 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -365,7 +365,7 @@ free_struct:
return status;
}

-static efi_status_t
+static void
setup_efi_pci32(struct boot_params *params, void **pci_handle,
unsigned long size)
{
@@ -408,8 +408,6 @@ setup_efi_pci32(struct boot_params *params, void **pci_handle,
data = (struct setup_data *)rom;

}
-
- return status;
}

static efi_status_t
@@ -468,7 +466,7 @@ free_struct:

}

-static efi_status_t
+static void
setup_efi_pci64(struct boot_params *params, void **pci_handle,
unsigned long size)
{
@@ -511,11 +509,18 @@ setup_efi_pci64(struct boot_params *params, void **pci_handle,
data = (struct setup_data *)rom;

}
-
- return status;
}

-static efi_status_t setup_efi_pci(struct boot_params *params)
+/*
+ * There's no way to return an informative status from this function,
+ * because any analysis (and printing of error messages) needs to be
+ * done directly at the EFI function call-site.
+ *
+ * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
+ * just didn't find any PCI devices, but there's no way to tell outside
+ * the context of the call.
+ */
+static void setup_efi_pci(struct boot_params *params)
{
efi_status_t status;
void **pci_handle = NULL;
@@ -532,7 +537,7 @@ static efi_status_t setup_efi_pci(struct boot_params *params)
size, (void **)&pci_handle);

if (status != EFI_SUCCESS)
- return status;
+ return;

status = efi_call_early(locate_handle,
EFI_LOCATE_BY_PROTOCOL, &pci_proto,
@@ -543,13 +548,12 @@ static efi_status_t setup_efi_pci(struct boot_params *params)
goto free_handle;

if (efi_early->is64)
- status = setup_efi_pci64(params, pci_handle, size);
+ setup_efi_pci64(params, pci_handle, size);
else
- status = setup_efi_pci32(params, pci_handle, size);
+ setup_efi_pci32(params, pci_handle, size);

free_handle:
efi_call_early(free_pool, pci_handle);
- return status;
}

static void
@@ -1385,10 +1389,7 @@ struct boot_params *efi_main(struct efi_config *c,

setup_graphics(boot_params);

- status = setup_efi_pci(boot_params);
- if (status != EFI_SUCCESS) {
- efi_printk(sys_table, "setup_efi_pci() failed!\n");
- }
+ setup_efi_pci(boot_params);

status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
sizeof(*gdt), (void **)&gdt);
--
1.9.3

--
Matt Fleming, Intel Open Source Technology Center