| Message ID | 20171012195937.24817-1-ard.biesheuvel@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | firmware: dmi: handle missing DMI data gracefully | expand |
Hi Ard, On Thu, 12 Oct 2017 20:59:37 +0100, Ard Biesheuvel wrote: > Currently, when booting a kernel with DMI support on a platform that has > no DMI tables, the following output is emitted into the kernel log: > > [ 0.128818] DMI not present or invalid. > ... > [ 1.306659] dmi: Firmware registration failed. > ... > [ 2.908681] dmi-sysfs: dmi entry is absent. > > The first one is a pr_info(), but the subsequent ones are pr_err()s that > complain about a condition that is not really an error to begin with. > > So let's clean this up, and give up silently if dma_available is not set. On the principle I agree, but you'll have to come up with an implementation that links successfully: ERROR: "dmi_available" [drivers/firmware/dmi-sysfs.ko] undefined! scripts/Makefile.modpost:91: recipe for target '__modpost' failed make[1]: *** [__modpost] Error 1 Makefile:1216: recipe for target 'modules' failed make: *** [modules] Error 2 The reason is that dmi_available is not exported. The obvious solution is to export it. Or maybe just turn the error message into a debug message and assume the only reason it may reasonably happen is because dmi isn't available in the first place. If dmi_kobj is missing for any other reason then there's a much more important problem to solve anyway. > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > drivers/firmware/dmi-sysfs.c | 3 +++ > drivers/firmware/dmi_scan.c | 6 ++---- > 2 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c > index d5de6ee8466d..3a264cbbb5a6 100644 > --- a/drivers/firmware/dmi-sysfs.c > +++ b/drivers/firmware/dmi-sysfs.c > @@ -651,6 +651,9 @@ static int __init dmi_sysfs_init(void) > int error; > int val; > > + if (!dmi_available) > + return 0; > + > if (!dmi_kobj) { > pr_err("dmi-sysfs: dmi entry is absent.\n"); > error = -ENODATA; > diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c > index 783041964439..17a7425063c2 100644 > --- a/drivers/firmware/dmi_scan.c > +++ b/drivers/firmware/dmi_scan.c > @@ -715,10 +715,8 @@ static int __init dmi_init(void) > u8 *dmi_table; > int ret = -ENOMEM; > > - if (!dmi_available) { > - ret = -ENODATA; > - goto err; > - } > + if (!dmi_available) > + return 0; > > /* > * Set up dmi directory at /sys/firmware/dmi. This entry should stay -- Jean Delvare SUSE L3 Support
On 17 October 2017 at 08:27, Jean Delvare <jdelvare@suse.de> wrote: > Hi Ard, > > On Thu, 12 Oct 2017 20:59:37 +0100, Ard Biesheuvel wrote: >> Currently, when booting a kernel with DMI support on a platform that has >> no DMI tables, the following output is emitted into the kernel log: >> >> [ 0.128818] DMI not present or invalid. >> ... >> [ 1.306659] dmi: Firmware registration failed. >> ... >> [ 2.908681] dmi-sysfs: dmi entry is absent. >> >> The first one is a pr_info(), but the subsequent ones are pr_err()s that >> complain about a condition that is not really an error to begin with. >> >> So let's clean this up, and give up silently if dma_available is not set. > > On the principle I agree, but you'll have to come up with an > implementation that links successfully: > > ERROR: "dmi_available" [drivers/firmware/dmi-sysfs.ko] undefined! > scripts/Makefile.modpost:91: recipe for target '__modpost' failed > make[1]: *** [__modpost] Error 1 > Makefile:1216: recipe for target 'modules' failed > make: *** [modules] Error 2 > Oops. Thanks for spotting that. > The reason is that dmi_available is not exported. The obvious solution > is to export it. Or maybe just turn the error message into a debug > message and assume the only reason it may reasonably happen is because > dmi isn't available in the first place. If dmi_kobj is missing for any > other reason then there's a much more important problem to solve anyway. > Indeed. dmi_kobj is the first thing that gets created in dmi_init(), and if that fails you will get a pr_err() anyway. I will respin. Thanks, Ard. >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> --- >> drivers/firmware/dmi-sysfs.c | 3 +++ >> drivers/firmware/dmi_scan.c | 6 ++---- >> 2 files changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c >> index d5de6ee8466d..3a264cbbb5a6 100644 >> --- a/drivers/firmware/dmi-sysfs.c >> +++ b/drivers/firmware/dmi-sysfs.c >> @@ -651,6 +651,9 @@ static int __init dmi_sysfs_init(void) >> int error; >> int val; >> >> + if (!dmi_available) >> + return 0; >> + >> if (!dmi_kobj) { >> pr_err("dmi-sysfs: dmi entry is absent.\n"); >> error = -ENODATA; >> diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c >> index 783041964439..17a7425063c2 100644 >> --- a/drivers/firmware/dmi_scan.c >> +++ b/drivers/firmware/dmi_scan.c >> @@ -715,10 +715,8 @@ static int __init dmi_init(void) >> u8 *dmi_table; >> int ret = -ENOMEM; >> >> - if (!dmi_available) { >> - ret = -ENODATA; >> - goto err; >> - } >> + if (!dmi_available) >> + return 0; >> >> /* >> * Set up dmi directory at /sys/firmware/dmi. This entry should stay > > -- > Jean Delvare > SUSE L3 Support
diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c index d5de6ee8466d..3a264cbbb5a6 100644 --- a/drivers/firmware/dmi-sysfs.c +++ b/drivers/firmware/dmi-sysfs.c @@ -651,6 +651,9 @@ static int __init dmi_sysfs_init(void) int error; int val; + if (!dmi_available) + return 0; + if (!dmi_kobj) { pr_err("dmi-sysfs: dmi entry is absent.\n"); error = -ENODATA; diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 783041964439..17a7425063c2 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -715,10 +715,8 @@ static int __init dmi_init(void) u8 *dmi_table; int ret = -ENOMEM; - if (!dmi_available) { - ret = -ENODATA; - goto err; - } + if (!dmi_available) + return 0; /* * Set up dmi directory at /sys/firmware/dmi. This entry should stay
Currently, when booting a kernel with DMI support on a platform that has no DMI tables, the following output is emitted into the kernel log: [ 0.128818] DMI not present or invalid. ... [ 1.306659] dmi: Firmware registration failed. ... [ 2.908681] dmi-sysfs: dmi entry is absent. The first one is a pr_info(), but the subsequent ones are pr_err()s that complain about a condition that is not really an error to begin with. So let's clean this up, and give up silently if dma_available is not set. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- drivers/firmware/dmi-sysfs.c | 3 +++ drivers/firmware/dmi_scan.c | 6 ++---- 2 files changed, 5 insertions(+), 4 deletions(-) -- 2.11.0