This is a backport of "iio: stm32-adc: fix a race with dma and irq" series on top of v4.14.148 at the time of writing. The original series doesn't apply cleanly on v4.14.x: the precursor patch needed a slight update.
Original series can be found in [1]. [1] https://www.lkml.org/lkml/2019/9/17/394
Original cover-letter: This series fixes a race condition observed when using several ADCs with DMA and irq. There's a precusor patch to the fix. It keeps registers definitions as a whole block, to ease readability and allow simple (readl) access path to EOC bits in stm32-adc-core driver.
Fabrice Gasnier (2): iio: adc: stm32-adc: move registers definitions iio: adc: stm32-adc: fix a race when using several adcs with dma and irq
drivers/iio/adc/stm32-adc-core.c | 70 +++++++++++--------- drivers/iio/adc/stm32-adc-core.h | 135 +++++++++++++++++++++++++++++++++++++++ drivers/iio/adc/stm32-adc.c | 107 ------------------------------- 3 files changed, 175 insertions(+), 137 deletions(-)
commit 31922f62bb527d749b99dbc776e514bcba29b7fe upstream.
Move STM32 ADC registers definitions to common header. This is precursor patch to: - iio: adc: stm32-adc: fix a race when using several adcs with dma and irq
It keeps registers definitions as a whole block, to ease readability and allow simple access path to EOC bits (readl) in stm32-adc-core driver.
Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support")
Signed-off-by: Fabrice Gasnier fabrice.gasnier@st.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/adc/stm32-adc-core.c | 27 -------- drivers/iio/adc/stm32-adc-core.h | 134 +++++++++++++++++++++++++++++++++++++++ drivers/iio/adc/stm32-adc.c | 107 ------------------------------- 3 files changed, 134 insertions(+), 134 deletions(-)
diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c index 804198e..b0d3468 100644 --- a/drivers/iio/adc/stm32-adc-core.c +++ b/drivers/iio/adc/stm32-adc-core.c @@ -33,36 +33,9 @@
#include "stm32-adc-core.h"
-/* STM32F4 - common registers for all ADC instances: 1, 2 & 3 */ -#define STM32F4_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00) -#define STM32F4_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x04) - -/* STM32F4_ADC_CSR - bit fields */ -#define STM32F4_EOC3 BIT(17) -#define STM32F4_EOC2 BIT(9) -#define STM32F4_EOC1 BIT(1) - -/* STM32F4_ADC_CCR - bit fields */ -#define STM32F4_ADC_ADCPRE_SHIFT 16 -#define STM32F4_ADC_ADCPRE_MASK GENMASK(17, 16) - /* STM32 F4 maximum analog clock rate (from datasheet) */ #define STM32F4_ADC_MAX_CLK_RATE 36000000
-/* STM32H7 - common registers for all ADC instances */ -#define STM32H7_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00) -#define STM32H7_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x08) - -/* STM32H7_ADC_CSR - bit fields */ -#define STM32H7_EOC_SLV BIT(18) -#define STM32H7_EOC_MST BIT(2) - -/* STM32H7_ADC_CCR - bit fields */ -#define STM32H7_PRESC_SHIFT 18 -#define STM32H7_PRESC_MASK GENMASK(21, 18) -#define STM32H7_CKMODE_SHIFT 16 -#define STM32H7_CKMODE_MASK GENMASK(17, 16) - /* STM32 H7 maximum analog clock rate (from datasheet) */ #define STM32H7_ADC_MAX_CLK_RATE 36000000
diff --git a/drivers/iio/adc/stm32-adc-core.h b/drivers/iio/adc/stm32-adc-core.h index 250ee95..2cb9bf8b 100644 --- a/drivers/iio/adc/stm32-adc-core.h +++ b/drivers/iio/adc/stm32-adc-core.h @@ -39,6 +39,140 @@ #define STM32_ADC_MAX_ADCS 3 #define STM32_ADCX_COMN_OFFSET 0x300
+/* STM32F4 - Registers for each ADC instance */ +#define STM32F4_ADC_SR 0x00 +#define STM32F4_ADC_CR1 0x04 +#define STM32F4_ADC_CR2 0x08 +#define STM32F4_ADC_SMPR1 0x0C +#define STM32F4_ADC_SMPR2 0x10 +#define STM32F4_ADC_HTR 0x24 +#define STM32F4_ADC_LTR 0x28 +#define STM32F4_ADC_SQR1 0x2C +#define STM32F4_ADC_SQR2 0x30 +#define STM32F4_ADC_SQR3 0x34 +#define STM32F4_ADC_JSQR 0x38 +#define STM32F4_ADC_JDR1 0x3C +#define STM32F4_ADC_JDR2 0x40 +#define STM32F4_ADC_JDR3 0x44 +#define STM32F4_ADC_JDR4 0x48 +#define STM32F4_ADC_DR 0x4C + +/* STM32F4 - common registers for all ADC instances: 1, 2 & 3 */ +#define STM32F4_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00) +#define STM32F4_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x04) + +/* STM32F4_ADC_SR - bit fields */ +#define STM32F4_STRT BIT(4) +#define STM32F4_EOC BIT(1) + +/* STM32F4_ADC_CR1 - bit fields */ +#define STM32F4_RES_SHIFT 24 +#define STM32F4_RES_MASK GENMASK(25, 24) +#define STM32F4_SCAN BIT(8) +#define STM32F4_EOCIE BIT(5) + +/* STM32F4_ADC_CR2 - bit fields */ +#define STM32F4_SWSTART BIT(30) +#define STM32F4_EXTEN_SHIFT 28 +#define STM32F4_EXTEN_MASK GENMASK(29, 28) +#define STM32F4_EXTSEL_SHIFT 24 +#define STM32F4_EXTSEL_MASK GENMASK(27, 24) +#define STM32F4_EOCS BIT(10) +#define STM32F4_DDS BIT(9) +#define STM32F4_DMA BIT(8) +#define STM32F4_ADON BIT(0) + +/* STM32F4_ADC_CSR - bit fields */ +#define STM32F4_EOC3 BIT(17) +#define STM32F4_EOC2 BIT(9) +#define STM32F4_EOC1 BIT(1) + +/* STM32F4_ADC_CCR - bit fields */ +#define STM32F4_ADC_ADCPRE_SHIFT 16 +#define STM32F4_ADC_ADCPRE_MASK GENMASK(17, 16) + +/* STM32H7 - Registers for each ADC instance */ +#define STM32H7_ADC_ISR 0x00 +#define STM32H7_ADC_IER 0x04 +#define STM32H7_ADC_CR 0x08 +#define STM32H7_ADC_CFGR 0x0C +#define STM32H7_ADC_SMPR1 0x14 +#define STM32H7_ADC_SMPR2 0x18 +#define STM32H7_ADC_PCSEL 0x1C +#define STM32H7_ADC_SQR1 0x30 +#define STM32H7_ADC_SQR2 0x34 +#define STM32H7_ADC_SQR3 0x38 +#define STM32H7_ADC_SQR4 0x3C +#define STM32H7_ADC_DR 0x40 +#define STM32H7_ADC_CALFACT 0xC4 +#define STM32H7_ADC_CALFACT2 0xC8 + +/* STM32H7 - common registers for all ADC instances */ +#define STM32H7_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00) +#define STM32H7_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x08) + +/* STM32H7_ADC_ISR - bit fields */ +#define STM32H7_EOC BIT(2) +#define STM32H7_ADRDY BIT(0) + +/* STM32H7_ADC_IER - bit fields */ +#define STM32H7_EOCIE STM32H7_EOC + +/* STM32H7_ADC_CR - bit fields */ +#define STM32H7_ADCAL BIT(31) +#define STM32H7_ADCALDIF BIT(30) +#define STM32H7_DEEPPWD BIT(29) +#define STM32H7_ADVREGEN BIT(28) +#define STM32H7_LINCALRDYW6 BIT(27) +#define STM32H7_LINCALRDYW5 BIT(26) +#define STM32H7_LINCALRDYW4 BIT(25) +#define STM32H7_LINCALRDYW3 BIT(24) +#define STM32H7_LINCALRDYW2 BIT(23) +#define STM32H7_LINCALRDYW1 BIT(22) +#define STM32H7_ADCALLIN BIT(16) +#define STM32H7_BOOST BIT(8) +#define STM32H7_ADSTP BIT(4) +#define STM32H7_ADSTART BIT(2) +#define STM32H7_ADDIS BIT(1) +#define STM32H7_ADEN BIT(0) + +/* STM32H7_ADC_CFGR bit fields */ +#define STM32H7_EXTEN_SHIFT 10 +#define STM32H7_EXTEN_MASK GENMASK(11, 10) +#define STM32H7_EXTSEL_SHIFT 5 +#define STM32H7_EXTSEL_MASK GENMASK(9, 5) +#define STM32H7_RES_SHIFT 2 +#define STM32H7_RES_MASK GENMASK(4, 2) +#define STM32H7_DMNGT_SHIFT 0 +#define STM32H7_DMNGT_MASK GENMASK(1, 0) + +enum stm32h7_adc_dmngt { + STM32H7_DMNGT_DR_ONLY, /* Regular data in DR only */ + STM32H7_DMNGT_DMA_ONESHOT, /* DMA one shot mode */ + STM32H7_DMNGT_DFSDM, /* DFSDM mode */ + STM32H7_DMNGT_DMA_CIRC, /* DMA circular mode */ +}; + +/* STM32H7_ADC_CALFACT - bit fields */ +#define STM32H7_CALFACT_D_SHIFT 16 +#define STM32H7_CALFACT_D_MASK GENMASK(26, 16) +#define STM32H7_CALFACT_S_SHIFT 0 +#define STM32H7_CALFACT_S_MASK GENMASK(10, 0) + +/* STM32H7_ADC_CALFACT2 - bit fields */ +#define STM32H7_LINCALFACT_SHIFT 0 +#define STM32H7_LINCALFACT_MASK GENMASK(29, 0) + +/* STM32H7_ADC_CSR - bit fields */ +#define STM32H7_EOC_SLV BIT(18) +#define STM32H7_EOC_MST BIT(2) + +/* STM32H7_ADC_CCR - bit fields */ +#define STM32H7_PRESC_SHIFT 18 +#define STM32H7_PRESC_MASK GENMASK(21, 18) +#define STM32H7_CKMODE_SHIFT 16 +#define STM32H7_CKMODE_MASK GENMASK(17, 16) + /** * struct stm32_adc_common - stm32 ADC driver common data (for all instances) * @base: control registers base cpu addr diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 04be8bd..e59cbc9 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -40,113 +40,6 @@
#include "stm32-adc-core.h"
-/* STM32F4 - Registers for each ADC instance */ -#define STM32F4_ADC_SR 0x00 -#define STM32F4_ADC_CR1 0x04 -#define STM32F4_ADC_CR2 0x08 -#define STM32F4_ADC_SMPR1 0x0C -#define STM32F4_ADC_SMPR2 0x10 -#define STM32F4_ADC_HTR 0x24 -#define STM32F4_ADC_LTR 0x28 -#define STM32F4_ADC_SQR1 0x2C -#define STM32F4_ADC_SQR2 0x30 -#define STM32F4_ADC_SQR3 0x34 -#define STM32F4_ADC_JSQR 0x38 -#define STM32F4_ADC_JDR1 0x3C -#define STM32F4_ADC_JDR2 0x40 -#define STM32F4_ADC_JDR3 0x44 -#define STM32F4_ADC_JDR4 0x48 -#define STM32F4_ADC_DR 0x4C - -/* STM32F4_ADC_SR - bit fields */ -#define STM32F4_STRT BIT(4) -#define STM32F4_EOC BIT(1) - -/* STM32F4_ADC_CR1 - bit fields */ -#define STM32F4_RES_SHIFT 24 -#define STM32F4_RES_MASK GENMASK(25, 24) -#define STM32F4_SCAN BIT(8) -#define STM32F4_EOCIE BIT(5) - -/* STM32F4_ADC_CR2 - bit fields */ -#define STM32F4_SWSTART BIT(30) -#define STM32F4_EXTEN_SHIFT 28 -#define STM32F4_EXTEN_MASK GENMASK(29, 28) -#define STM32F4_EXTSEL_SHIFT 24 -#define STM32F4_EXTSEL_MASK GENMASK(27, 24) -#define STM32F4_EOCS BIT(10) -#define STM32F4_DDS BIT(9) -#define STM32F4_DMA BIT(8) -#define STM32F4_ADON BIT(0) - -/* STM32H7 - Registers for each ADC instance */ -#define STM32H7_ADC_ISR 0x00 -#define STM32H7_ADC_IER 0x04 -#define STM32H7_ADC_CR 0x08 -#define STM32H7_ADC_CFGR 0x0C -#define STM32H7_ADC_SMPR1 0x14 -#define STM32H7_ADC_SMPR2 0x18 -#define STM32H7_ADC_PCSEL 0x1C -#define STM32H7_ADC_SQR1 0x30 -#define STM32H7_ADC_SQR2 0x34 -#define STM32H7_ADC_SQR3 0x38 -#define STM32H7_ADC_SQR4 0x3C -#define STM32H7_ADC_DR 0x40 -#define STM32H7_ADC_CALFACT 0xC4 -#define STM32H7_ADC_CALFACT2 0xC8 - -/* STM32H7_ADC_ISR - bit fields */ -#define STM32H7_EOC BIT(2) -#define STM32H7_ADRDY BIT(0) - -/* STM32H7_ADC_IER - bit fields */ -#define STM32H7_EOCIE STM32H7_EOC - -/* STM32H7_ADC_CR - bit fields */ -#define STM32H7_ADCAL BIT(31) -#define STM32H7_ADCALDIF BIT(30) -#define STM32H7_DEEPPWD BIT(29) -#define STM32H7_ADVREGEN BIT(28) -#define STM32H7_LINCALRDYW6 BIT(27) -#define STM32H7_LINCALRDYW5 BIT(26) -#define STM32H7_LINCALRDYW4 BIT(25) -#define STM32H7_LINCALRDYW3 BIT(24) -#define STM32H7_LINCALRDYW2 BIT(23) -#define STM32H7_LINCALRDYW1 BIT(22) -#define STM32H7_ADCALLIN BIT(16) -#define STM32H7_BOOST BIT(8) -#define STM32H7_ADSTP BIT(4) -#define STM32H7_ADSTART BIT(2) -#define STM32H7_ADDIS BIT(1) -#define STM32H7_ADEN BIT(0) - -/* STM32H7_ADC_CFGR bit fields */ -#define STM32H7_EXTEN_SHIFT 10 -#define STM32H7_EXTEN_MASK GENMASK(11, 10) -#define STM32H7_EXTSEL_SHIFT 5 -#define STM32H7_EXTSEL_MASK GENMASK(9, 5) -#define STM32H7_RES_SHIFT 2 -#define STM32H7_RES_MASK GENMASK(4, 2) -#define STM32H7_DMNGT_SHIFT 0 -#define STM32H7_DMNGT_MASK GENMASK(1, 0) - -enum stm32h7_adc_dmngt { - STM32H7_DMNGT_DR_ONLY, /* Regular data in DR only */ - STM32H7_DMNGT_DMA_ONESHOT, /* DMA one shot mode */ - STM32H7_DMNGT_DFSDM, /* DFSDM mode */ - STM32H7_DMNGT_DMA_CIRC, /* DMA circular mode */ -}; - -/* STM32H7_ADC_CALFACT - bit fields */ -#define STM32H7_CALFACT_D_SHIFT 16 -#define STM32H7_CALFACT_D_MASK GENMASK(26, 16) -#define STM32H7_CALFACT_S_SHIFT 0 -#define STM32H7_CALFACT_S_MASK GENMASK(10, 0) - -/* STM32H7_ADC_CALFACT2 - bit fields */ -#define STM32H7_LINCALFACT_SHIFT 0 -#define STM32H7_LINCALFACT_MASK GENMASK(29, 0) - /* Number of linear calibration shadow registers / LINCALRDYW control bits */ #define STM32H7_LINCALFACT_NUM 6
commit dcb10920179ab74caf88a6f2afadecfc2743b910 upstream.
End of conversion may be handled by using IRQ or DMA. There may be a race when two conversions complete at the same time on several ADCs. EOC can be read as 'set' for several ADCs, with: - an ADC configured to use IRQs. EOCIE bit is set. The handler is normally called in this case. - an ADC configured to use DMA. EOCIE bit isn't set. EOC triggers the DMA request instead. It's then automatically cleared by DMA read. But the handler gets called due to status bit is temporarily set (IRQ triggered by the other ADC). So both EOC status bit in CSR and EOCIE control bit must be checked before invoking the interrupt handler (e.g. call ISR only for IRQ-enabled ADCs).
Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support")
Signed-off-by: Fabrice Gasnier fabrice.gasnier@st.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/adc/stm32-adc-core.c | 43 +++++++++++++++++++++++++++++++++++++--- drivers/iio/adc/stm32-adc-core.h | 1 + 2 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c index b0d3468..bc9ebcc 100644 --- a/drivers/iio/adc/stm32-adc-core.c +++ b/drivers/iio/adc/stm32-adc-core.c @@ -45,12 +45,16 @@ * @eoc1: adc1 end of conversion flag in @csr * @eoc2: adc2 end of conversion flag in @csr * @eoc3: adc3 end of conversion flag in @csr + * @ier: interrupt enable register offset for each adc + * @eocie_msk: end of conversion interrupt enable mask in @ier */ struct stm32_adc_common_regs { u32 csr; u32 eoc1_msk; u32 eoc2_msk; u32 eoc3_msk; + u32 ier; + u32 eocie_msk; };
struct stm32_adc_priv; @@ -244,6 +248,8 @@ static const struct stm32_adc_common_regs stm32f4_adc_common_regs = { .eoc1_msk = STM32F4_EOC1, .eoc2_msk = STM32F4_EOC2, .eoc3_msk = STM32F4_EOC3, + .ier = STM32F4_ADC_CR1, + .eocie_msk = STM32F4_EOCIE, };
/* STM32H7 common registers definitions */ @@ -251,8 +257,24 @@ static const struct stm32_adc_common_regs stm32h7_adc_common_regs = { .csr = STM32H7_ADC_CSR, .eoc1_msk = STM32H7_EOC_MST, .eoc2_msk = STM32H7_EOC_SLV, + .ier = STM32H7_ADC_IER, + .eocie_msk = STM32H7_EOCIE, };
+static const unsigned int stm32_adc_offset[STM32_ADC_MAX_ADCS] = { + 0, STM32_ADC_OFFSET, STM32_ADC_OFFSET * 2, +}; + +static unsigned int stm32_adc_eoc_enabled(struct stm32_adc_priv *priv, + unsigned int adc) +{ + u32 ier, offset = stm32_adc_offset[adc]; + + ier = readl_relaxed(priv->common.base + offset + priv->cfg->regs->ier); + + return ier & priv->cfg->regs->eocie_msk; +} + /* ADC common interrupt for all instances */ static void stm32_adc_irq_handler(struct irq_desc *desc) { @@ -263,13 +285,28 @@ static void stm32_adc_irq_handler(struct irq_desc *desc) chained_irq_enter(chip, desc); status = readl_relaxed(priv->common.base + priv->cfg->regs->csr);
- if (status & priv->cfg->regs->eoc1_msk) + /* + * End of conversion may be handled by using IRQ or DMA. There may be a + * race here when two conversions complete at the same time on several + * ADCs. EOC may be read 'set' for several ADCs, with: + * - an ADC configured to use DMA (EOC triggers the DMA request, and + * is then automatically cleared by DR read in hardware) + * - an ADC configured to use IRQs (EOCIE bit is set. The handler must + * be called in this case) + * So both EOC status bit in CSR and EOCIE control bit must be checked + * before invoking the interrupt handler (e.g. call ISR only for + * IRQ-enabled ADCs). + */ + if (status & priv->cfg->regs->eoc1_msk && + stm32_adc_eoc_enabled(priv, 0)) generic_handle_irq(irq_find_mapping(priv->domain, 0));
- if (status & priv->cfg->regs->eoc2_msk) + if (status & priv->cfg->regs->eoc2_msk && + stm32_adc_eoc_enabled(priv, 1)) generic_handle_irq(irq_find_mapping(priv->domain, 1));
- if (status & priv->cfg->regs->eoc3_msk) + if (status & priv->cfg->regs->eoc3_msk && + stm32_adc_eoc_enabled(priv, 2)) generic_handle_irq(irq_find_mapping(priv->domain, 2));
chained_irq_exit(chip, desc); diff --git a/drivers/iio/adc/stm32-adc-core.h b/drivers/iio/adc/stm32-adc-core.h index 2cb9bf8b..9f8559c 100644 --- a/drivers/iio/adc/stm32-adc-core.h +++ b/drivers/iio/adc/stm32-adc-core.h @@ -37,6 +37,7 @@ * -------------------------------------------------------- */ #define STM32_ADC_MAX_ADCS 3 +#define STM32_ADC_OFFSET 0x100 #define STM32_ADCX_COMN_OFFSET 0x300
/* STM32F4 - Registers for each ADC instance */
On Wed, Oct 16, 2019 at 03:44:53PM +0200, Fabrice Gasnier wrote:
This is a backport of "iio: stm32-adc: fix a race with dma and irq" series on top of v4.14.148 at the time of writing. The original series doesn't apply cleanly on v4.14.x: the precursor patch needed a slight update.
Original series can be found in [1]. [1] https://www.lkml.org/lkml/2019/9/17/394
Now queued up,t hanks.
greg k-h
linux-stable-mirror@lists.linaro.org
-
Fabrice Gasnier -
Greg KH