[PATCH v2 15/15] gpio: stmpe: i2c transfer are forbiden in atomic context
From: patrice.chotard
Date: Tue Jan 16 2018 - 07:37:13 EST
From: Patrice Chotard <patrice.chotard@xxxxxx>
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>
---
drivers/gpio/gpio-stmpe.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c
index e6e5cca..91c8ae2 100644
--- a/drivers/gpio/gpio-stmpe.c
+++ b/drivers/gpio/gpio-stmpe.c
@@ -190,6 +190,16 @@ static void stmpe_gpio_irq_sync_unlock(struct irq_data *d)
};
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 irq_data *d)
{
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,
--
1.9.1