This is a note to let you know that I've just added the patch titled gpio: stmpe: i2c transfer are forbiden in atomic context to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: gpio-stmpe-i2c-transfer-are-forbiden-in-atomic-context.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b888fb6f2a278442933e3bfab70262e9a5365fb3 Mon Sep 17 00:00:00 2001 From: Patrice Chotard <patrice.chotard@xxxxxx> Date: Fri, 12 Jan 2018 13:16:08 +0100 Subject: gpio: stmpe: i2c transfer are forbiden in atomic context From: Patrice Chotard <patrice.chotard@xxxxxx> commit b888fb6f2a278442933e3bfab70262e9a5365fb3 upstream. Move the workaround from stmpe_gpio_irq_unmask() which is executed in atomic context to stmpe_gpio_irq_sync_unlock() which is not. It fixes the following issue: [ 1.500000] BUG: scheduling while atomic: swapper/1/0x00000002 [ 1.500000] CPU: 0 PID: 1 Comm: swapper Not tainted 4.15.0-rc2-00020-gbd4301f-dirty #28 [ 1.520000] Hardware name: STM32 (Device Tree Support) [ 1.520000] [<0000bfc9>] (unwind_backtrace) from [<0000b347>] (show_stack+0xb/0xc) [ 1.530000] [<0000b347>] (show_stack) from [<0001fc49>] (__schedule_bug+0x39/0x58) [ 1.530000] [<0001fc49>] (__schedule_bug) from [<00168211>] (__schedule+0x23/0x2b2) [ 1.550000] [<00168211>] (__schedule) from [<001684f7>] (schedule+0x57/0x64) [ 1.550000] [<001684f7>] (schedule) from [<0016a513>] (schedule_timeout+0x137/0x164) [ 1.550000] [<0016a513>] (schedule_timeout) from [<00168b91>] (wait_for_common+0x8d/0xfc) [ 1.570000] [<00168b91>] (wait_for_common) from [<00139753>] (stm32f4_i2c_xfer+0xe9/0xfe) [ 1.580000] [<00139753>] (stm32f4_i2c_xfer) from [<00138545>] (__i2c_transfer+0x111/0x148) [ 1.590000] [<00138545>] (__i2c_transfer) from [<001385cf>] (i2c_transfer+0x53/0x70) [ 1.590000] [<001385cf>] (i2c_transfer) from [<001388a5>] (i2c_smbus_xfer+0x12f/0x36e) [ 1.600000] [<001388a5>] (i2c_smbus_xfer) from [<00138b49>] (i2c_smbus_read_byte_data+0x1f/0x2a) [ 1.610000] [<00138b49>] (i2c_smbus_read_byte_data) from [<00124fdd>] (__stmpe_reg_read+0xd/0x24) [ 1.620000] [<00124fdd>] (__stmpe_reg_read) from [<001252b3>] (stmpe_reg_read+0x19/0x24) [ 1.630000] [<001252b3>] (stmpe_reg_read) from [<0002c4d1>] (unmask_irq+0x17/0x22) [ 1.640000] [<0002c4d1>] (unmask_irq) from [<0002c57f>] (irq_startup+0x6f/0x78) [ 1.650000] [<0002c57f>] (irq_startup) from [<0002b7a1>] (__setup_irq+0x319/0x47c) [ 1.650000] [<0002b7a1>] (__setup_irq) from [<0002bad3>] (request_threaded_irq+0x6b/0xe8) [ 1.660000] [<0002bad3>] (request_threaded_irq) from [<0002d0b9>] (devm_request_threaded_irq+0x3b/0x6a) [ 1.670000] [<0002d0b9>] (devm_request_threaded_irq) from [<001446e7>] (mmc_gpiod_request_cd_irq+0x49/0x8a) [ 1.680000] [<001446e7>] (mmc_gpiod_request_cd_irq) from [<0013d45d>] (mmc_start_host+0x49/0x60) [ 1.690000] [<0013d45d>] (mmc_start_host) from [<0013e40b>] (mmc_add_host+0x3b/0x54) [ 1.700000] [<0013e40b>] (mmc_add_host) from [<00148119>] (mmci_probe+0x4d1/0x60c) [ 1.710000] [<00148119>] (mmci_probe) from [<000f903b>] (amba_probe+0x7b/0xbe) [ 1.720000] [<000f903b>] (amba_probe) from [<001170e5>] (driver_probe_device+0x169/0x1f8) [ 1.730000] [<001170e5>] (driver_probe_device) from [<001171b7>] (__driver_attach+0x43/0x5c) [ 1.740000] [<001171b7>] (__driver_attach) from [<0011618d>] (bus_for_each_dev+0x3d/0x46) [ 1.740000] [<0011618d>] (bus_for_each_dev) from [<001165cd>] (bus_add_driver+0xcd/0x124) [ 1.740000] [<001165cd>] (bus_add_driver) from [<00117713>] (driver_register+0x4d/0x7a) [ 1.760000] [<00117713>] (driver_register) from [<001fc765>] (do_one_initcall+0xbd/0xe8) [ 1.770000] [<001fc765>] (do_one_initcall) from [<001fc88b>] (kernel_init_freeable+0xfb/0x134) [ 1.780000] [<001fc88b>] (kernel_init_freeable) from [<00167ee3>] (kernel_init+0x7/0x9c) [ 1.790000] [<00167ee3>] (kernel_init) from [<00009b65>] (ret_from_fork+0x11/0x2c) Signed-off-by: Alexandre TORGUE <alexandre.torgue@xxxxxx> Signed-off-by: Patrice Chotard <patrice.chotard@xxxxxx> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpio/gpio-stmpe.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) --- a/drivers/gpio/gpio-stmpe.c +++ b/drivers/gpio/gpio-stmpe.c @@ -190,6 +190,16 @@ static void stmpe_gpio_irq_sync_unlock(s }; int i, j; + /* + * STMPE1600: to be able to get IRQ from pins, + * a read must be done on GPMR register, or a write in + * GPSR or GPCR registers + */ + if (stmpe->partnum == STMPE1600) { + stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]); + stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]); + } + for (i = 0; i < CACHE_NR_REGS; i++) { /* STMPE801 and STMPE1600 don't have RE and FE registers */ if ((stmpe->partnum == STMPE801 || @@ -227,21 +237,11 @@ static void stmpe_gpio_irq_unmask(struct { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc); - struct stmpe *stmpe = stmpe_gpio->stmpe; int offset = d->hwirq; int regoffset = offset / 8; int mask = BIT(offset % 8); stmpe_gpio->regs[REG_IE][regoffset] |= mask; - - /* - * STMPE1600 workaround: to be able to get IRQ from pins, - * a read must be done on GPMR register, or a write in - * GPSR or GPCR registers - */ - if (stmpe->partnum == STMPE1600) - stmpe_reg_read(stmpe, - stmpe->regs[STMPE_IDX_GPMR_LSB + regoffset]); } static void stmpe_dbg_show_one(struct seq_file *s, Patches currently in stable-queue which might be from patrice.chotard@xxxxxx are queue-4.15/gpio-stmpe-i2c-transfer-are-forbiden-in-atomic-context.patch