On Tue, May 21, 2013 at 6:51 PM, Jonghwan Choi <jhbird.c...@samsung.com> wrote: > This patch looks like it should be in the 3.9-stable tree, should we apply > it? >
Good point, since you've already copied this email to stable mail list. I guess it should be OK for them review. Thanks, -Bryan > ------------------ > > From: "Timo Teras <timo.te...@iki.fi>" > > commit 803d19d57a042e86e9e9b685bbc3f4a0a751040f upstream > > This reverts commit a99d76f (leds: leds-gpio: use gpio_request_one) > and commit 2d7c22f (leds: leds-gpio: set devm_gpio_request_one() > flags param correctly) which was a fix of the first one. > > The conversion to devm_gpio_request in commit e3b1d44c (leds: > leds-gpio: use devm_gpio_request_one) is not reverted. > > The problem is that gpio_cansleep() and gpio_get_value_cansleep() > calls can crash if the gpio is not first reserved. Incidentally this > same bug existed earlier and was fixed similarly in commit d95cbe61 > (leds: Fix potential leds-gpio oops). But the OOPS is real. It happens > when GPIOs are provided by module which is not yet loaded. > > So this fixes the following BUG during my ALIX boot (3.9.2-vanilla): > > BUG: unable to handle kernel NULL pointer dereference at 0000004c > IP: [<c11287d6>] __gpio_cansleep+0xe/0x1a > *pde = 00000000 > Oops: 0000 [#1] SMP > Modules linked in: leds_gpio(+) via_rhine mii cs5535_mfd mfd_core > geode_rng rng_core geode_aes isofs nls_utf8 nls_cp437 vfat fat > ata_generic pata_amd pata_cs5536 pata_acpi libata ehci_pci ehci_hcd > ohci_hcd usb_storage usbcore usb_common sd_mod scsi_mod squashfs loop > Pid: 881, comm: modprobe Not tainted 3.9.2 #1-Alpine > EIP: 0060:[<c11287d6>] EFLAGS: 00010282 CPU: 0 > EIP is at __gpio_cansleep+0xe/0x1a > EAX: 00000000 EBX: cf364018 ECX: c132b8b9 EDX: 00000000 > ESI: c13993a4 EDI: c1399370 EBP: cded9dbc ESP: cded9dbc > DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 > CR0: 8005003b CR2: 0000004c CR3: 0f0c4000 CR4: 00000090 > DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 > DR6: ffff0ff0 DR7: 00000400 > Process modprobe (pid: 881, ti=cded8000 task=cf094aa0 task.ti=cded8000) > Stack: > cded9de0 d09471cb 00000000 c1399260 cf364014 00000000 c1399260 c1399254 > d0949014 cded9df4 c118cd59 c1399260 d0949014 d0949014 cded9e08 c118ba47 > c1399260 d0949014 c1399294 cded9e1c c118bb75 cded9e24 d0949014 00000000 > Call Trace: > [<d09471cb>] gpio_led_probe+0xba/0x203 [leds_gpio] > [<c118cd59>] platform_drv_probe+0x26/0x48 > [<c118ba47>] driver_probe_device+0x75/0x15c > [<c118bb75>] __driver_attach+0x47/0x63 > [<c118a727>] bus_for_each_dev+0x3c/0x66 > [<c118b6f9>] driver_attach+0x14/0x16 > [<c118bb2e>] ? driver_probe_device+0x15c/0x15c > [<c118b3d5>] bus_add_driver+0xbd/0x1bc > [<d08b4000>] ? 0xd08b3fff > [<d08b4000>] ? 0xd08b3fff > [<c118bffc>] driver_register+0x74/0xec > [<d08b4000>] ? 0xd08b3fff > [<c118c8e8>] platform_driver_register+0x38/0x3a > [<d08b400d>] gpio_led_driver_init+0xd/0x1000 [leds_gpio] > [<c100116c>] do_one_initcall+0x6b/0x10f > [<d08b4000>] ? 0xd08b3fff > [<c105e918>] load_module+0x1631/0x1907 > [<c10975d6>] ? insert_vmalloc_vmlist+0x14/0x43 > [<c1098d5b>] ? __vmalloc_node_range+0x13e/0x15f > [<c105ec50>] sys_init_module+0x62/0x77 > [<c1257888>] syscall_call+0x7/0xb > EIP: [<c11287d6>] __gpio_cansleep+0xe/0x1a SS:ESP 0068:cded9dbc > CR2: 000000000000004c > ---[ end trace 5308fb20d2514822 ]--- > > Signed-off-by: Timo Teras <timo.te...@iki.fi> > Cc: Sachin Kamat <sachin.ka...@linaro.org> > Cc: Raphael Assenat <r...@8d.com> > Cc: Trent Piepho <tpie...@freescale.com> > Cc: Javier Martinez Canillas <javier.marti...@collabora.co.uk> > Cc: Arnaud Patard <arnaud.pat...@rtp-net.org> > Cc: Ezequiel Garcia <ezequiel.gar...@free-electrons.com> > Acked-by: Jingoo Han <jg1....@samsung.com> > Signed-off-by: Bryan Wu <coolo...@gmail.com> > Signed-off-by: Jonghwan Choi <jhbird.c...@samsung.com> > --- > drivers/leds/leds-gpio.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c > index a0d931b..b02b679 100644 > --- a/drivers/leds/leds-gpio.c > +++ b/drivers/leds/leds-gpio.c > @@ -107,6 +107,10 @@ static int create_gpio_led(const struct gpio_led > *template, > return 0; > } > > + ret = devm_gpio_request(parent, template->gpio, template->name); > + if (ret < 0) > + return ret; > + > led_dat->cdev.name = template->name; > led_dat->cdev.default_trigger = template->default_trigger; > led_dat->gpio = template->gpio; > @@ -126,10 +130,7 @@ static int create_gpio_led(const struct gpio_led > *template, > if (!template->retain_state_suspended) > led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; > > - ret = devm_gpio_request_one(parent, template->gpio, > - (led_dat->active_low ^ state) ? > - GPIOF_OUT_INIT_HIGH : > GPIOF_OUT_INIT_LOW, > - template->name); > + ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ > state); > if (ret < 0) > return ret; > > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
