This patchset is to resolve an issue found with Nuvoton pinctrl driver
when it uses a generic GPIO interface. Since the generic GPIO driver
stores the bgpio_data and bgpio_dir shadow register values and later on
modify based on the stored values, any change to the pin states in
between by the pinctrl driver is lost.
Kun Yi (2):
gpio: gpio-mmio: Allow volatile shadow regs
pinctrl: pinctrl-npcm7xx: Set BGPIOF_VOLATILE_REG
drivers/gpio/gpio-mmio.c | 50 +++++++++++++++--------
drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c | 3 +-
include/linux/gpio/driver.h | 2 +
3 files changed, 38 insertions(+), 17 deletions(-)
--
2.19.1.331.ge82ca0e54c-goog
Currently the generic GPIO driver stores the direction and data shadow register
when the driver probes. However, in embedded SOCs the GPIO pins are often
interleaved with pins muxed to other functions, and pinctrl driver might
toggle the direction/data register values for these pins. With GPIO
driver being not the only owner, it should read the shadow registers
before updating them, otherwise some pin states would be overwritten.
This patch adds a flag BGPIOF_VOLATILE_REG to allow a pinctrl driver that uses
the generic GPIO interface to indicate the need of read-before-update.
Signed-off-by: Kun Yi <[email protected]>
---
drivers/gpio/gpio-mmio.c | 50 +++++++++++++++++++++++++------------
include/linux/gpio/driver.h | 2 ++
2 files changed, 36 insertions(+), 16 deletions(-)
diff --git a/drivers/gpio/gpio-mmio.c b/drivers/gpio/gpio-mmio.c
index 935292a30c99..5e13e43a793d 100644
--- a/drivers/gpio/gpio-mmio.c
+++ b/drivers/gpio/gpio-mmio.c
@@ -136,7 +136,12 @@ static unsigned long bgpio_line2mask(struct gpio_chip *gc, unsigned int line)
static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)
{
unsigned long pinmask = bgpio_line2mask(gc, gpio);
- bool dir = !!(gc->bgpio_dir & pinmask);
+ bool dir;
+
+ if (gc->bgpio_regs_are_volatile)
+ gc->bgpio_dir = gc->read_reg(gc->reg_dir);
+
+ dir = !!(gc->bgpio_dir & pinmask);
/*
* If the direction is OUT we read the value from the SET
@@ -168,6 +173,9 @@ static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask,
/* Make sure we first clear any bits that are zero when we read the register */
*bits &= ~*mask;
+ if (gc->bgpio_regs_are_volatile)
+ gc->bgpio_dir = gc->read_reg(gc->reg_dir);
+
/* Exploit the fact that we know which directions are set */
if (gc->bgpio_dir_inverted) {
set_mask = *mask & ~gc->bgpio_dir;
@@ -238,21 +246,31 @@ static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
{
}
-static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+static void bgpio_set_single_reg(struct gpio_chip *gc, unsigned int gpio,
+ int val, void __iomem *reg)
{
unsigned long mask = bgpio_line2mask(gc, gpio);
unsigned long flags;
spin_lock_irqsave(&gc->bgpio_lock, flags);
+ if (gc->bgpio_regs_are_volatile)
+ gc->bgpio_data = gc->read_reg(reg);
+
if (val)
gc->bgpio_data |= mask;
else
gc->bgpio_data &= ~mask;
- gc->write_reg(gc->reg_dat, gc->bgpio_data);
+ gc->write_reg(reg, gc->bgpio_data);
spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+
+}
+
+static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+ bgpio_set_single_reg(gc, gpio, val, gc->reg_dat);
}
static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
@@ -268,19 +286,7 @@ static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
- unsigned long mask = bgpio_line2mask(gc, gpio);
- unsigned long flags;
-
- spin_lock_irqsave(&gc->bgpio_lock, flags);
-
- if (val)
- gc->bgpio_data |= mask;
- else
- gc->bgpio_data &= ~mask;
-
- gc->write_reg(gc->reg_set, gc->bgpio_data);
-
- spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+ bgpio_set_single_reg(gc, gpio, val, gc->reg_set);
}
static void bgpio_multiple_get_masks(struct gpio_chip *gc,
@@ -317,6 +323,9 @@ static void bgpio_set_multiple_single_reg(struct gpio_chip *gc,
bgpio_multiple_get_masks(gc, mask, bits, &set_mask, &clear_mask);
+ if (gc->bgpio_regs_are_volatile)
+ gc->bgpio_data = gc->read_reg(reg);
+
gc->bgpio_data |= set_mask;
gc->bgpio_data &= ~clear_mask;
@@ -376,6 +385,9 @@ static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
spin_lock_irqsave(&gc->bgpio_lock, flags);
+ if (gc->bgpio_regs_are_volatile)
+ gc->bgpio_dir = gc->read_reg(gc->reg_dir);
+
if (gc->bgpio_dir_inverted)
gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
else
@@ -404,6 +416,9 @@ static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
spin_lock_irqsave(&gc->bgpio_lock, flags);
+ if (gc->bgpio_regs_are_volatile)
+ gc->bgpio_dir = gc->read_reg(gc->reg_dir);
+
if (gc->bgpio_dir_inverted)
gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
else
@@ -641,6 +656,9 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
if (gc->reg_dir && !(flags & BGPIOF_UNREADABLE_REG_DIR))
gc->bgpio_dir = gc->read_reg(gc->reg_dir);
+ if (flags & BGPIOF_VOLATILE_REG)
+ gc->bgpio_regs_are_volatile = true;
+
return ret;
}
EXPORT_SYMBOL_GPL(bgpio_init);
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 0ea328e71ec9..a889037daf20 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -274,6 +274,7 @@ struct gpio_chip {
spinlock_t bgpio_lock;
unsigned long bgpio_data;
unsigned long bgpio_dir;
+ bool bgpio_regs_are_volatile;
#endif
#ifdef CONFIG_GPIOLIB_IRQCHIP
@@ -428,6 +429,7 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
#define BGPIOF_BIG_ENDIAN_BYTE_ORDER BIT(3)
#define BGPIOF_READ_OUTPUT_REG_SET BIT(4) /* reg_set stores output value */
#define BGPIOF_NO_OUTPUT BIT(5) /* only input */
+#define BGPIOF_VOLATILE_REG BIT(6) /* update shadow before writing*/
#endif
--
2.19.1.331.ge82ca0e54c-goog
Indicate that the pins are both controlled by the pinctrl driver and the
generic GPIO driver, thus GPIO driver should read the register value
before updating, instead of using the stored shadow register values.
Signed-off-by: Kun Yi <[email protected]>
---
drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c b/drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c
index 7ad50d9268aa..ac7b69d53aff 100644
--- a/drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c
+++ b/drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c
@@ -1904,7 +1904,8 @@ static int npcm7xx_gpio_of(struct npcm7xx_pinctrl *pctrl)
NULL,
pctrl->gpio_bank[id].base +
NPCM7XX_GP_N_IEM,
- BGPIOF_READ_OUTPUT_REG_SET);
+ BGPIOF_READ_OUTPUT_REG_SET |
+ BGPIOF_VOLATILE_REG);
if (ret) {
dev_err(pctrl->dev, "bgpio_init() failed\n");
return ret;
--
2.19.1.331.ge82ca0e54c-goog
Hi Kun,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on gpio/for-next]
[also build test WARNING on v4.19-rc8 next-20181018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Kun-Yi/gpio-gpio-mmio-Allow-volatile-shadow-regs/20181018-144115
base: https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git for-next
reproduce: make htmldocs
All warnings (new ones prefixed by >>):
WARNING: convert(1) not found, for SVG to PDF conversion install ImageMagick (https://www.imagemagick.org)
include/linux/srcu.h:175: warning: Function parameter or member 'p' not described in 'srcu_dereference_notrace'
include/linux/srcu.h:175: warning: Function parameter or member 'sp' not described in 'srcu_dereference_notrace'
include/linux/gfp.h:1: warning: no structured comments found
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.ibss' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.connect' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.keys' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.ie' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.ie_len' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.bssid' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.ssid' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.default_key' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.default_mgmt_key' not described in 'wireless_dev'
include/net/cfg80211.h:4381: warning: Function parameter or member 'wext.prev_bssid_valid' not described in 'wireless_dev'
include/net/mac80211.h:2328: warning: Function parameter or member 'radiotap_timestamp.units_pos' not described in 'ieee80211_hw'
include/net/mac80211.h:2328: warning: Function parameter or member 'radiotap_timestamp.accuracy' not described in 'ieee80211_hw'
include/net/mac80211.h:977: warning: Function parameter or member 'control.rates' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.rts_cts_rate_idx' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.use_rts' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.use_cts_prot' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.short_preamble' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.skip_table' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.jiffies' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.vif' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.hw_key' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.flags' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'control.enqueue_time' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'ack' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'ack.cookie' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.rates' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.ack_signal' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.ampdu_ack_len' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.ampdu_len' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.antenna' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.tx_time' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.is_valid_ack_signal' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.status_driver_data' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'driver_rates' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'pad' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'rate_driver_data' not described in 'ieee80211_tx_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'rx_stats_avg' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'rx_stats_avg.signal' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'rx_stats_avg.chain_signal' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.filtered' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.retry_failed' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.retry_count' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.lost_packets' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.last_tdls_pkt_time' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.msdu_retries' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.msdu_failed' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.last_ack' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.last_ack_signal' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.ack_signal_filled' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.avg_ack_signal' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'tx_stats.packets' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'tx_stats.bytes' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'tx_stats.last_rate' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'tx_stats.msdu' not described in 'sta_info'
include/linux/mod_devicetable.h:763: warning: Function parameter or member 'driver_data' not described in 'typec_device_id'
kernel/sched/fair.c:3371: warning: Function parameter or member 'flags' not described in 'attach_entity_load_avg'
arch/x86/include/asm/atomic.h:84: warning: Excess function parameter 'i' description in 'arch_atomic_sub_and_test'
arch/x86/include/asm/atomic.h:84: warning: Excess function parameter 'v' description in 'arch_atomic_sub_and_test'
arch/x86/include/asm/atomic.h:96: warning: Excess function parameter 'v' description in 'arch_atomic_inc'
arch/x86/include/asm/atomic.h:109: warning: Excess function parameter 'v' description in 'arch_atomic_dec'
arch/x86/include/asm/atomic.h:124: warning: Excess function parameter 'v' description in 'arch_atomic_dec_and_test'
arch/x86/include/asm/atomic.h:138: warning: Excess function parameter 'v' description in 'arch_atomic_inc_and_test'
arch/x86/include/asm/atomic.h:153: warning: Excess function parameter 'i' description in 'arch_atomic_add_negative'
arch/x86/include/asm/atomic.h:153: warning: Excess function parameter 'v' description in 'arch_atomic_add_negative'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.cb' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.poll' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.active' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.cb' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.poll' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.active' not described in 'dma_buf'
include/linux/dma-fence-array.h:54: warning: Function parameter or member 'work' not described in 'dma_fence_array'
include/linux/gpio/driver.h:369: warning: Function parameter or member 'init_valid_mask' not described in 'gpio_chip'
>> include/linux/gpio/driver.h:369: warning: Function parameter or member 'bgpio_regs_are_volatile' not described in 'gpio_chip'
include/linux/iio/hw-consumer.h:1: warning: no structured comments found
include/linux/input/sparse-keymap.h:46: warning: Function parameter or member 'sw' not described in 'key_entry'
drivers/pci/pci.c:218: warning: Excess function parameter 'p' description in 'pci_dev_str_match_path'
include/linux/regulator/driver.h:227: warning: Function parameter or member 'resume' not described in 'regulator_ops'
drivers/regulator/core.c:4479: warning: Excess function parameter 'state' description in 'regulator_suspend'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw0' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw1' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw2' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw3' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.eadm' not described in 'irb'
drivers/slimbus/stream.c:1: warning: no structured comments found
drivers/target/target_core_device.c:1: warning: no structured comments found
drivers/usb/dwc3/gadget.c:510: warning: Excess function parameter 'dwc' description in 'dwc3_gadget_start_config'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/bus.c:1: warning: no structured comments found
drivers/usb/typec/bus.c:268: warning: Function parameter or member 'mode' not described in 'typec_match_altmode'
drivers/usb/typec/class.c:1497: warning: Excess function parameter 'drvdata' description in 'typec_port_register_altmode'
drivers/usb/typec/class.c:1: warning: no structured comments found
include/linux/w1.h:281: warning: Function parameter or member 'of_match_table' not described in 'w1_family'
fs/direct-io.c:257: warning: Excess function parameter 'offset' description in 'dio_complete'
fs/file_table.c:1: warning: no structured comments found
fs/libfs.c:477: warning: Excess function parameter 'available' description in 'simple_write_end'
fs/posix_acl.c:646: warning: Function parameter or member 'inode' not described in 'posix_acl_update_mode'
fs/posix_acl.c:646: warning: Function parameter or member 'mode_p' not described in 'posix_acl_update_mode'
fs/posix_acl.c:646: warning: Function parameter or member 'acl' not described in 'posix_acl_update_mode'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:183: warning: Function parameter or member 'blockable' not described in 'amdgpu_mn_read_lock'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:254: warning: Function parameter or member 'blockable' not described in 'amdgpu_mn_invalidate_range_start_gfx'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:302: warning: Function parameter or member 'blockable' not described in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2986: warning: Excess function parameter 'dev' description in 'amdgpu_vm_get_task_info'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2987: warning: Function parameter or member 'adev' not described in 'amdgpu_vm_get_task_info'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:2987: warning: Excess function parameter 'dev' description in 'amdgpu_vm_get_task_info'
include/drm/drm_drv.h:610: warning: Function parameter or member 'gem_prime_pin' not described in 'drm_driver'
include/drm/drm_drv.h:610: warning: Function parameter or member 'gem_prime_unpin' not described in 'drm_driver'
include/drm/drm_drv.h:610: warning: Function parameter or member 'gem_prime_res_obj' not described in 'drm_driver'
include/drm/drm_drv.h:610: warning: Function parameter or member 'gem_prime_get_sg_table' not described in 'drm_driver'
include/drm/drm_drv.h:610: warning: Function parameter or member 'gem_prime_import_sg_table' not described in 'drm_driver'
include/drm/drm_drv.h:610: warning: Function parameter or member 'gem_prime_vmap' not described in 'drm_driver'
include/drm/drm_drv.h:610: warning: Function parameter or member 'gem_prime_vunmap' not described in 'drm_driver'
include/drm/drm_drv.h:610: warning: Function parameter or member 'gem_prime_mmap' not described in 'drm_driver'
include/drm/drm_panel.h:98: warning: Function parameter or member 'link' not described in 'drm_panel'
drivers/gpu/drm/i915/i915_vma.h:49: warning: cannot understand function prototype: 'struct i915_vma '
drivers/gpu/drm/i915/i915_vma.h:1: warning: no structured comments found
drivers/gpu/drm/i915/intel_guc_fwif.h:553: warning: cannot understand function prototype: 'struct guc_log_buffer_state '
drivers/gpu/drm/i915/i915_trace.h:1: warning: no structured comments found
include/linux/skbuff.h:860: warning: Function parameter or member 'dev_scratch' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'list' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'ip_defrag_offset' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'skb_mstamp' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member '__cloned_offset' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'head_frag' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member '__pkt_type_offset' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'encapsulation' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'encap_hdr_csum' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'csum_valid' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'csum_complete_sw' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'csum_level' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'inner_protocol_type' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'remcsum_offload' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'offload_fwd_mark' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'offload_mr_fwd_mark' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'sender_cpu' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'reserved_tailroom' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'inner_ipproto' not described in 'sk_buff'
include/net/sock.h:238: warning: Function parameter or member 'skc_addrpair' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_portpair' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_ipv6only' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_net_refcnt' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_v6_daddr' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_v6_rcv_saddr' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_cookie' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_listener' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_tw_dr' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_rcv_wnd' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_tw_rcv_nxt' not described in 'sock_common'
include/net/sock.h:509: warning: Function parameter or member 'sk_backlog.rmem_alloc' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_backlog.len' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_backlog.head' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_backlog.tail' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_wq_raw' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'tcp_rtx_queue' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_route_forced_caps' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_txtime_report_errors' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_validate_xmit_skb' not described in 'sock'
include/linux/netdevice.h:2018: warning: Function parameter or member 'adj_list.upper' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'adj_list.lower' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'gso_partial_features' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'switchdev_ops' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'l3mdev_ops' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'xfrmdev_ops' not described in 'net_device'
vim +369 include/linux/gpio/driver.h
79a9becd Alexandre Courbot 2013-10-17 @369
:::::: The code at line 369 was first introduced by commit
:::::: 79a9becda8940deb2274b5aa4577c86d52ee7ecb gpiolib: export descriptor-based GPIO interface
:::::: TO: Alexandre Courbot <[email protected]>
:::::: CC: Linus Walleij <[email protected]>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Wed, Oct 17, 2018 at 11:30 PM Kun Yi <[email protected]> wrote:
> Indicate that the pins are both controlled by the pinctrl driver and the
> generic GPIO driver, thus GPIO driver should read the register value
> before updating, instead of using the stored shadow register values.
>
> Signed-off-by: Kun Yi <[email protected]>
This is quite a rough measure, if we instead use regmap-mmio
we can exercise fine control over what register are volatile and
not instead of saying that all of them or some of them are.
Yours,
Linus Walleij
On Wed, Oct 17, 2018 at 11:30 PM Kun Yi <[email protected]> wrote:
> Currently the generic GPIO driver stores the direction and data shadow register
> when the driver probes. However, in embedded SOCs the GPIO pins are often
> interleaved with pins muxed to other functions, and pinctrl driver might
> toggle the direction/data register values for these pins. With GPIO
> driver being not the only owner, it should read the shadow registers
> before updating them, otherwise some pin states would be overwritten.
>
> This patch adds a flag BGPIOF_VOLATILE_REG to allow a pinctrl driver that uses
> the generic GPIO interface to indicate the need of read-before-update.
>
> Signed-off-by: Kun Yi <[email protected]>
Hi Kun,
as you see the build robot has problems with the patch, please look
into it.
Architecturally I'm not so sure about this, we are introducing more
and more "shadow registers" and I feel what happens at the end
of the day is that we end up reimplementing regmap-mmio.
Please look into switching gpio-mmio.c to use regmap-mmio
and add more registers based on that.
It might be a bit complex but is a way better way forward for
everyone.
Yours,
Linus Walleij
On Tue, Oct 30, 2018 at 5:08 AM Linus Walleij <[email protected]> wrote:
>
> On Wed, Oct 17, 2018 at 11:30 PM Kun Yi <[email protected]> wrote:
>
> > Indicate that the pins are both controlled by the pinctrl driver and the
> > generic GPIO driver, thus GPIO driver should read the register value
> > before updating, instead of using the stored shadow register values.
> >
> > Signed-off-by: Kun Yi <[email protected]>
>
> This is quite a rough measure, if we instead use regmap-mmio
> we can exercise fine control over what register are volatile and
> not instead of saying that all of them or some of them are.
Thanks for your review Linus! I don't have time to rewrite using
regmap-mmio at the moment though. I have discussed with the driver
author and we will first patch the pinctrl driver by making the
pinctrl functions use the gpio-mmio accessors instead of directly reg
read/writes. When I have time I will look into your suggestion to
improve the driver.
>
> Yours,
> Linus Walleij
--
Regards,
Kun