From: Enrico Granata <[email protected]>
If one builds the Chrome EC support as modules, there is no explicit
dependency chain amongst the several modules (LPC, CHARDEV, CORE, ...)
This makes it possible - for instance - to rmmod cros_ec_core, even though
cros_ec_dev actively uses it for data transport to the EC chip.
This commit makes two changes in an attempt to address this:
a) moves cros_ec_proto.c as part of the CORE module; this removes the
possibility of unloading cros_ec_core while cros_ec_dev is using it;
b) enables cros_ec_core to explicitly register a runtime dependency on
the kernel module that is using its cmd and pkt transfer functions
Signed-off-by: Enrico Granata <[email protected]>
---
drivers/mfd/Kconfig | 1 -
drivers/mfd/Makefile | 2 +-
drivers/mfd/cros_ec.c | 17 ++++++++++++++++-
.../{platform/chrome => mfd}/cros_ec_proto.c | 0
drivers/platform/chrome/Kconfig | 5 -----
drivers/platform/chrome/Makefile | 1 -
drivers/platform/chrome/cros_ec_lpc.c | 1 +
include/linux/mfd/cros_ec.h | 2 ++
8 files changed, 20 insertions(+), 9 deletions(-)
rename drivers/{platform/chrome => mfd}/cros_ec_proto.c (100%)
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b860eb5aa194..a8daa2072ae6 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -194,7 +194,6 @@ config MFD_CROS_EC
tristate "ChromeOS Embedded Controller"
select MFD_CORE
select CHROME_PLATFORMS
- select CROS_EC_PROTO
depends on X86 || ARM || ARM64 || COMPILE_TEST
help
If you say Y here you get support for the ChromeOS Embedded
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index d9d2cf0d32ef..20537bd27695 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -12,7 +12,7 @@ obj-$(CONFIG_MFD_SM501) += sm501.o
obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o
obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
obj-$(CONFIG_MFD_BD9571MWV) += bd9571mwv.o
-cros_ec_core-objs := cros_ec.o
+cros_ec_core-objs := cros_ec.o cros_ec_proto.o
cros_ec_core-$(CONFIG_ACPI) += cros_ec_acpi_gpe.o
obj-$(CONFIG_MFD_CROS_EC) += cros_ec_core.o
obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index d61024141e2b..109e9cb1e289 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -168,9 +168,21 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
*/
err = cros_ec_sleep_event(ec_dev, 0);
if (err < 0)
- dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
+ dev_dbg(dev, "Error %d clearing sleep event to ec",
err);
+ if (ec_dev->xfer_fcn_owner != NULL) {
+ err = try_module_get(ec_dev->xfer_fcn_owner);
+ if (err < 0) {
+ dev_err(dev, "Error %d acquiring transfer module", err);
+ return err;
+ }
+ dev_info(dev, "Transfer module %p get successfully",
+ ec_dev->xfer_fcn_owner);
+ } else {
+ dev_warn(dev, "No transfer module registered");
+ }
+
dev_info(dev, "Chrome EC device registered\n");
cros_ec_acpi_install_gpe_handler(dev);
@@ -193,6 +205,9 @@ int cros_ec_remove(struct cros_ec_device *ec_dev)
if (ec_dev->irq)
free_irq(ec_dev->irq, ec_dev);
+ if (ec_dev->xfer_fcn_owner != NULL)
+ module_put(ec_dev->xfer_fcn_owner);
+
return 0;
}
EXPORT_SYMBOL(cros_ec_remove);
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/mfd/cros_ec_proto.c
similarity index 100%
rename from drivers/platform/chrome/cros_ec_proto.c
rename to drivers/mfd/cros_ec_proto.c
diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index e728a96cabfd..a050c9e8b506 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -65,11 +65,6 @@ config CROS_EC_LPC_MEC
If you have a ChromeOS Embedded Controller Microchip EC variant
choose Y here.
-config CROS_EC_PROTO
- bool
- help
- ChromeOS EC communication protocol helpers.
-
config CROS_KBD_LED_BACKLIGHT
tristate "Backlight LED support for Chrome OS keyboards"
depends on LEDS_CLASS && ACPI
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index ff3b369911f0..0b5e26ca9c96 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -8,5 +8,4 @@ obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
-obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index 3682e1539251..8f02b188bd3f 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -282,6 +282,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
ec_dev->phys_name = dev_name(dev);
ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
+ ec_dev->xfer_fcn_owner = THIS_MODULE;
ec_dev->cmd_readmem = cros_ec_lpc_readmem;
ec_dev->din_size = sizeof(struct ec_host_response) +
sizeof(struct ec_response_get_protocol_info);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 2d4e23c9ea0a..5239107e5091 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -18,6 +18,7 @@
#include <linux/cdev.h>
#include <linux/device.h>
+#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/mutex.h>
@@ -139,6 +140,7 @@ struct cros_ec_device {
int dout_size;
bool wake_enabled;
bool suspended;
+ struct module *xfer_fcn_owner;
int (*cmd_xfer)(struct cros_ec_device *ec,
struct cros_ec_command *msg);
int (*pkt_xfer)(struct cros_ec_device *ec,
--
2.17.1.1185.g55be947832-goog
On Mon, Jun 4, 2018 at 1:22 PM Enrico Granata <[email protected]> wrote:
>
> From: Enrico Granata <[email protected]>
>
> If one builds the Chrome EC support as modules, there is no explicit
> dependency chain amongst the several modules (LPC, CHARDEV, CORE, ...)
>
> This makes it possible - for instance - to rmmod cros_ec_core, even though
> cros_ec_dev actively uses it for data transport to the EC chip.
>
> This commit makes two changes in an attempt to address this:
> a) moves cros_ec_proto.c as part of the CORE module; this removes the
> possibility of unloading cros_ec_core while cros_ec_dev is using it;
> b) enables cros_ec_core to explicitly register a runtime dependency on
> the kernel module that is using its cmd and pkt transfer functions
>
> Signed-off-by: Enrico Granata <[email protected]>
> ---
>
> drivers/mfd/Kconfig | 1 -
> drivers/mfd/Makefile | 2 +-
> drivers/mfd/cros_ec.c | 17 ++++++++++++++++-
> .../{platform/chrome => mfd}/cros_ec_proto.c | 0
> drivers/platform/chrome/Kconfig | 5 -----
> drivers/platform/chrome/Makefile | 1 -
> drivers/platform/chrome/cros_ec_lpc.c | 1 +
> include/linux/mfd/cros_ec.h | 2 ++
> 8 files changed, 20 insertions(+), 9 deletions(-)
> rename drivers/{platform/chrome => mfd}/cros_ec_proto.c (100%)
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index b860eb5aa194..a8daa2072ae6 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -194,7 +194,6 @@ config MFD_CROS_EC
> tristate "ChromeOS Embedded Controller"
> select MFD_CORE
> select CHROME_PLATFORMS
> - select CROS_EC_PROTO
> depends on X86 || ARM || ARM64 || COMPILE_TEST
> help
> If you say Y here you get support for the ChromeOS Embedded
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index d9d2cf0d32ef..20537bd27695 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -12,7 +12,7 @@ obj-$(CONFIG_MFD_SM501) += sm501.o
> obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o
> obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
> obj-$(CONFIG_MFD_BD9571MWV) += bd9571mwv.o
> -cros_ec_core-objs := cros_ec.o
> +cros_ec_core-objs := cros_ec.o cros_ec_proto.o
We try to get cros_ec_proto out of mfd directory, it is weird to
compile something from drivers/platform/chrome/ in drivers/mfd.
> cros_ec_core-$(CONFIG_ACPI) += cros_ec_acpi_gpe.o
> obj-$(CONFIG_MFD_CROS_EC) += cros_ec_core.o
> obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index d61024141e2b..109e9cb1e289 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -168,9 +168,21 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> */
> err = cros_ec_sleep_event(ec_dev, 0);
> if (err < 0)
> - dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
> + dev_dbg(dev, "Error %d clearing sleep event to ec",
> err);
Concatenate both line.
>
> + if (ec_dev->xfer_fcn_owner != NULL) {
> + err = try_module_get(ec_dev->xfer_fcn_owner);
> + if (err < 0) {
> + dev_err(dev, "Error %d acquiring transfer module", err);
> + return err;
> + }
> + dev_info(dev, "Transfer module %p get successfully",
> + ec_dev->xfer_fcn_owner);
> + } else {
> + dev_warn(dev, "No transfer module registered");
> + }
> +
> dev_info(dev, "Chrome EC device registered\n");
>
> cros_ec_acpi_install_gpe_handler(dev);
> @@ -193,6 +205,9 @@ int cros_ec_remove(struct cros_ec_device *ec_dev)
> if (ec_dev->irq)
> free_irq(ec_dev->irq, ec_dev);
>
> + if (ec_dev->xfer_fcn_owner != NULL)
> + module_put(ec_dev->xfer_fcn_owner);
> +
> return 0;
> }
> EXPORT_SYMBOL(cros_ec_remove);
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/mfd/cros_ec_proto.c
> similarity index 100%
> rename from drivers/platform/chrome/cros_ec_proto.c
> rename to drivers/mfd/cros_ec_proto.c
> diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
> index e728a96cabfd..a050c9e8b506 100644
> --- a/drivers/platform/chrome/Kconfig
> +++ b/drivers/platform/chrome/Kconfig
> @@ -65,11 +65,6 @@ config CROS_EC_LPC_MEC
> If you have a ChromeOS Embedded Controller Microchip EC variant
> choose Y here.
>
> -config CROS_EC_PROTO
> - bool
> - help
> - ChromeOS EC communication protocol helpers.
> -
> config CROS_KBD_LED_BACKLIGHT
> tristate "Backlight LED support for Chrome OS keyboards"
> depends on LEDS_CLASS && ACPI
> diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
> index ff3b369911f0..0b5e26ca9c96 100644
> --- a/drivers/platform/chrome/Makefile
> +++ b/drivers/platform/chrome/Makefile
> @@ -8,5 +8,4 @@ obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
> cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
> cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
> obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
> -obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
> obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
> diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
> index 3682e1539251..8f02b188bd3f 100644
> --- a/drivers/platform/chrome/cros_ec_lpc.c
> +++ b/drivers/platform/chrome/cros_ec_lpc.c
> @@ -282,6 +282,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
> ec_dev->phys_name = dev_name(dev);
> ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
> ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
> + ec_dev->xfer_fcn_owner = THIS_MODULE;
You need to modify other transport modules as well:
cros_ec_i2c.c, cros_ec_spi.c.
> ec_dev->cmd_readmem = cros_ec_lpc_readmem;
> ec_dev->din_size = sizeof(struct ec_host_response) +
> sizeof(struct ec_response_get_protocol_info);
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index 2d4e23c9ea0a..5239107e5091 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -18,6 +18,7 @@
>
> #include <linux/cdev.h>
> #include <linux/device.h>
> +#include <linux/module.h>
> #include <linux/notifier.h>
> #include <linux/mfd/cros_ec_commands.h>
> #include <linux/mutex.h>
> @@ -139,6 +140,7 @@ struct cros_ec_device {
> int dout_size;
> bool wake_enabled;
> bool suspended;
> + struct module *xfer_fcn_owner;
Another solution would be to make cros_ec a real module. lpc depends
on cros_ec_register, so lsmod will not unload cros_ec [core functions]
if cros_ec_lpc is still loaded.
> int (*cmd_xfer)(struct cros_ec_device *ec,
> struct cros_ec_command *msg);
> int (*pkt_xfer)(struct cros_ec_device *ec,
> --
> 2.17.1.1185.g55be947832-goog
>
From: Enrico Granata <[email protected]>
If one builds the Chrome EC support as modules, there is no explicit
dependency chain amongst the several modules (LPC, CHARDEV, CORE, ...)
This makes it possible - for instance - to rmmod cros_ec_core, even though
cros_ec_dev actively uses it for data transport to the EC chip.
This commit makes two changes in an attempt to address this:
a) moves cros_ec_proto.c as part of the CORE module; this removes the
possibility of unloading cros_ec_core while cros_ec_dev is using it;
b) enables cros_ec_core to explicitly register a runtime dependency on
the kernel module that is using its cmd and pkt transfer functions
Series-to: LKML <[email protected]>
Series-cc: [email protected]
Signed-off-by: Enrico Granata <[email protected]>
---
drivers/mfd/Kconfig | 1 -
drivers/mfd/Makefile | 2 +-
drivers/mfd/cros_ec.c | 17 ++++++++++++++++-
.../{platform/chrome => mfd}/cros_ec_proto.c | 0
drivers/platform/chrome/Kconfig | 5 -----
drivers/platform/chrome/Makefile | 1 -
drivers/platform/chrome/cros_ec_lpc.c | 1 +
include/linux/mfd/cros_ec.h | 2 ++
8 files changed, 20 insertions(+), 9 deletions(-)
rename drivers/{platform/chrome => mfd}/cros_ec_proto.c (100%)
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b860eb5aa194..a8daa2072ae6 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -194,7 +194,6 @@ config MFD_CROS_EC
tristate "ChromeOS Embedded Controller"
select MFD_CORE
select CHROME_PLATFORMS
- select CROS_EC_PROTO
depends on X86 || ARM || ARM64 || COMPILE_TEST
help
If you say Y here you get support for the ChromeOS Embedded
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index d9d2cf0d32ef..20537bd27695 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -12,7 +12,7 @@ obj-$(CONFIG_MFD_SM501) += sm501.o
obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o
obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
obj-$(CONFIG_MFD_BD9571MWV) += bd9571mwv.o
-cros_ec_core-objs := cros_ec.o
+cros_ec_core-objs := cros_ec.o cros_ec_proto.o
cros_ec_core-$(CONFIG_ACPI) += cros_ec_acpi_gpe.o
obj-$(CONFIG_MFD_CROS_EC) += cros_ec_core.o
obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index d61024141e2b..109e9cb1e289 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -168,9 +168,21 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
*/
err = cros_ec_sleep_event(ec_dev, 0);
if (err < 0)
- dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
+ dev_dbg(dev, "Error %d clearing sleep event to ec",
err);
+ if (ec_dev->xfer_fcn_owner != NULL) {
+ err = try_module_get(ec_dev->xfer_fcn_owner);
+ if (err < 0) {
+ dev_err(dev, "Error %d acquiring transfer module", err);
+ return err;
+ }
+ dev_info(dev, "Transfer module %p get successfully",
+ ec_dev->xfer_fcn_owner);
+ } else {
+ dev_warn(dev, "No transfer module registered");
+ }
+
dev_info(dev, "Chrome EC device registered\n");
cros_ec_acpi_install_gpe_handler(dev);
@@ -193,6 +205,9 @@ int cros_ec_remove(struct cros_ec_device *ec_dev)
if (ec_dev->irq)
free_irq(ec_dev->irq, ec_dev);
+ if (ec_dev->xfer_fcn_owner != NULL)
+ module_put(ec_dev->xfer_fcn_owner);
+
return 0;
}
EXPORT_SYMBOL(cros_ec_remove);
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/mfd/cros_ec_proto.c
similarity index 100%
rename from drivers/platform/chrome/cros_ec_proto.c
rename to drivers/mfd/cros_ec_proto.c
diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index e728a96cabfd..a050c9e8b506 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -65,11 +65,6 @@ config CROS_EC_LPC_MEC
If you have a ChromeOS Embedded Controller Microchip EC variant
choose Y here.
-config CROS_EC_PROTO
- bool
- help
- ChromeOS EC communication protocol helpers.
-
config CROS_KBD_LED_BACKLIGHT
tristate "Backlight LED support for Chrome OS keyboards"
depends on LEDS_CLASS && ACPI
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index ff3b369911f0..0b5e26ca9c96 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -8,5 +8,4 @@ obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
-obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index 3682e1539251..8f02b188bd3f 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -282,6 +282,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
ec_dev->phys_name = dev_name(dev);
ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
+ ec_dev->xfer_fcn_owner = THIS_MODULE;
ec_dev->cmd_readmem = cros_ec_lpc_readmem;
ec_dev->din_size = sizeof(struct ec_host_response) +
sizeof(struct ec_response_get_protocol_info);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 2d4e23c9ea0a..5239107e5091 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -18,6 +18,7 @@
#include <linux/cdev.h>
#include <linux/device.h>
+#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/mutex.h>
@@ -139,6 +140,7 @@ struct cros_ec_device {
int dout_size;
bool wake_enabled;
bool suspended;
+ struct module *xfer_fcn_owner;
int (*cmd_xfer)(struct cros_ec_device *ec,
struct cros_ec_command *msg);
int (*pkt_xfer)(struct cros_ec_device *ec,
--
2.17.1.1185.g55be947832-goog
From: Enrico Granata <[email protected]>
If one builds the Chrome EC support as modules, there is no explicit
dependency chain amongst the several modules (LPC, CHARDEV, CORE, ...)
This makes it possible - for instance - to rmmod cros_ec_core, even though
cros_ec_dev actively uses it for data transport to the EC chip.
This commit makes two changes in an attempt to address this:
a) moves cros_ec_proto.c as part of the CORE module; this removes the
possibility of unloading cros_ec_core while cros_ec_dev is using it;
b) enables cros_ec_core to explicitly register a runtime dependency on
the kernel module that is using its cmd and pkt transfer functions
Series-to: LKML <[email protected]>
Series-cc: [email protected]
Signed-off-by: Enrico Granata <[email protected]>
---
drivers/mfd/Kconfig | 1 -
drivers/mfd/Makefile | 2 +-
drivers/mfd/cros_ec.c | 18 ++++++++++++++++--
drivers/mfd/cros_ec_i2c.c | 1 +
drivers/{platform/chrome => mfd}/cros_ec_proto.c | 0
drivers/mfd/cros_ec_spi.c | 1 +
drivers/platform/chrome/Kconfig | 5 -----
drivers/platform/chrome/Makefile | 1 -
drivers/platform/chrome/cros_ec_lpc.c | 1 +
include/linux/mfd/cros_ec.h | 2 ++
10 files changed, 22 insertions(+), 10 deletions(-)
rename drivers/{platform/chrome => mfd}/cros_ec_proto.c (100%)
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b860eb5aa194..a8daa2072ae6 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -194,7 +194,6 @@ config MFD_CROS_EC
tristate "ChromeOS Embedded Controller"
select MFD_CORE
select CHROME_PLATFORMS
- select CROS_EC_PROTO
depends on X86 || ARM || ARM64 || COMPILE_TEST
help
If you say Y here you get support for the ChromeOS Embedded
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index d9d2cf0d32ef..20537bd27695 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -12,7 +12,7 @@ obj-$(CONFIG_MFD_SM501) += sm501.o
obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o
obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
obj-$(CONFIG_MFD_BD9571MWV) += bd9571mwv.o
-cros_ec_core-objs := cros_ec.o
+cros_ec_core-objs := cros_ec.o cros_ec_proto.o
cros_ec_core-$(CONFIG_ACPI) += cros_ec_acpi_gpe.o
obj-$(CONFIG_MFD_CROS_EC) += cros_ec_core.o
obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index d61024141e2b..9660dc0fc079 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -168,8 +168,19 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
*/
err = cros_ec_sleep_event(ec_dev, 0);
if (err < 0)
- dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
- err);
+ dev_dbg(dev, "Error %d clearing sleep event to ec", err);
+
+ if (ec_dev->xfer_fcn_owner != NULL) {
+ err = try_module_get(ec_dev->xfer_fcn_owner);
+ if (err < 0) {
+ dev_err(dev, "Error %d acquiring transfer module", err);
+ return err;
+ }
+ dev_info(dev, "Transfer module %p get successfully",
+ ec_dev->xfer_fcn_owner);
+ } else {
+ dev_warn(dev, "No transfer module registered");
+ }
dev_info(dev, "Chrome EC device registered\n");
@@ -193,6 +204,9 @@ int cros_ec_remove(struct cros_ec_device *ec_dev)
if (ec_dev->irq)
free_irq(ec_dev->irq, ec_dev);
+ if (ec_dev->xfer_fcn_owner != NULL)
+ module_put(ec_dev->xfer_fcn_owner);
+
return 0;
}
EXPORT_SYMBOL(cros_ec_remove);
diff --git a/drivers/mfd/cros_ec_i2c.c b/drivers/mfd/cros_ec_i2c.c
index 9f70de1e4c70..72b0473eb868 100644
--- a/drivers/mfd/cros_ec_i2c.c
+++ b/drivers/mfd/cros_ec_i2c.c
@@ -302,6 +302,7 @@ static int cros_ec_i2c_probe(struct i2c_client *client,
ec_dev->irq = client->irq;
ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_i2c;
+ ec_dev->xfer_fcn_owner = THIS_MODULE;
ec_dev->phys_name = client->adapter->name;
ec_dev->din_size = sizeof(struct ec_host_response_i2c) +
sizeof(struct ec_response_get_protocol_info);
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/mfd/cros_ec_proto.c
similarity index 100%
rename from drivers/platform/chrome/cros_ec_proto.c
rename to drivers/mfd/cros_ec_proto.c
diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c
index 2060d1483043..ce2849790b95 100644
--- a/drivers/mfd/cros_ec_spi.c
+++ b/drivers/mfd/cros_ec_spi.c
@@ -666,6 +666,7 @@ static int cros_ec_spi_probe(struct spi_device *spi)
ec_dev->irq = spi->irq;
ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;
+ ec_dev->xfer_fcn_owner = THIS_MODULE;
ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
sizeof(struct ec_host_response) +
diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index e728a96cabfd..a050c9e8b506 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -65,11 +65,6 @@ config CROS_EC_LPC_MEC
If you have a ChromeOS Embedded Controller Microchip EC variant
choose Y here.
-config CROS_EC_PROTO
- bool
- help
- ChromeOS EC communication protocol helpers.
-
config CROS_KBD_LED_BACKLIGHT
tristate "Backlight LED support for Chrome OS keyboards"
depends on LEDS_CLASS && ACPI
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index ff3b369911f0..0b5e26ca9c96 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -8,5 +8,4 @@ obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
-obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index 3682e1539251..8f02b188bd3f 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -282,6 +282,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
ec_dev->phys_name = dev_name(dev);
ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
+ ec_dev->xfer_fcn_owner = THIS_MODULE;
ec_dev->cmd_readmem = cros_ec_lpc_readmem;
ec_dev->din_size = sizeof(struct ec_host_response) +
sizeof(struct ec_response_get_protocol_info);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 2d4e23c9ea0a..5239107e5091 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -18,6 +18,7 @@
#include <linux/cdev.h>
#include <linux/device.h>
+#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/mutex.h>
@@ -139,6 +140,7 @@ struct cros_ec_device {
int dout_size;
bool wake_enabled;
bool suspended;
+ struct module *xfer_fcn_owner;
int (*cmd_xfer)(struct cros_ec_device *ec,
struct cros_ec_command *msg);
int (*pkt_xfer)(struct cros_ec_device *ec,
--
2.17.1.1185.g55be947832-goog
On Mon, 04 Jun 2018, Enrico Granata wrote:
> From: Enrico Granata <[email protected]>
>
> If one builds the Chrome EC support as modules, there is no explicit
> dependency chain amongst the several modules (LPC, CHARDEV, CORE, ...)
>
> This makes it possible - for instance - to rmmod cros_ec_core, even though
> cros_ec_dev actively uses it for data transport to the EC chip.
>
> This commit makes two changes in an attempt to address this:
> a) moves cros_ec_proto.c as part of the CORE module; this removes the
> possibility of unloading cros_ec_core while cros_ec_dev is using it;
> b) enables cros_ec_core to explicitly register a runtime dependency on
> the kernel module that is using its cmd and pkt transfer functions
>
> Series-to: LKML <[email protected]>
> Series-cc: [email protected]
> Signed-off-by: Enrico Granata <[email protected]>
> ---
> drivers/mfd/Kconfig | 1 -
> drivers/mfd/Makefile | 2 +-
> drivers/mfd/cros_ec.c | 18 ++++++++++++++++--
> drivers/mfd/cros_ec_i2c.c | 1 +
> drivers/{platform/chrome => mfd}/cros_ec_proto.c | 0
> drivers/mfd/cros_ec_spi.c | 1 +
> drivers/platform/chrome/Kconfig | 5 -----
> drivers/platform/chrome/Makefile | 1 -
> drivers/platform/chrome/cros_ec_lpc.c | 1 +
> include/linux/mfd/cros_ec.h | 2 ++
> 10 files changed, 22 insertions(+), 10 deletions(-)
> rename drivers/{platform/chrome => mfd}/cros_ec_proto.c (100%)
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index b860eb5aa194..a8daa2072ae6 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -194,7 +194,6 @@ config MFD_CROS_EC
> tristate "ChromeOS Embedded Controller"
> select MFD_CORE
> select CHROME_PLATFORMS
> - select CROS_EC_PROTO
> depends on X86 || ARM || ARM64 || COMPILE_TEST
> help
> If you say Y here you get support for the ChromeOS Embedded
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index d9d2cf0d32ef..20537bd27695 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -12,7 +12,7 @@ obj-$(CONFIG_MFD_SM501) += sm501.o
> obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o
> obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
> obj-$(CONFIG_MFD_BD9571MWV) += bd9571mwv.o
> -cros_ec_core-objs := cros_ec.o
> +cros_ec_core-objs := cros_ec.o cros_ec_proto.o
> cros_ec_core-$(CONFIG_ACPI) += cros_ec_acpi_gpe.o
> obj-$(CONFIG_MFD_CROS_EC) += cros_ec_core.o
> obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index d61024141e2b..9660dc0fc079 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -168,8 +168,19 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> */
> err = cros_ec_sleep_event(ec_dev, 0);
> if (err < 0)
> - dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
> - err);
> + dev_dbg(dev, "Error %d clearing sleep event to ec", err);
This change is unrelated to the patch.
> + if (ec_dev->xfer_fcn_owner != NULL) {
if (ec_dev->xfer_fcn_owner) ?
> + err = try_module_get(ec_dev->xfer_fcn_owner);
> + if (err < 0) {
This logic is wrong. try_module_get() returns a bool.
> + dev_err(dev, "Error %d acquiring transfer module", err);
> + return err;
> + }
> + dev_info(dev, "Transfer module %p get successfully",
> + ec_dev->xfer_fcn_owner);
> + } else {
> + dev_warn(dev, "No transfer module registered");
> + }
>
> dev_info(dev, "Chrome EC device registered\n");
>
> @@ -193,6 +204,9 @@ int cros_ec_remove(struct cros_ec_device *ec_dev)
> if (ec_dev->irq)
> free_irq(ec_dev->irq, ec_dev);
>
> + if (ec_dev->xfer_fcn_owner != NULL)
As above.
> + module_put(ec_dev->xfer_fcn_owner);
> +
> return 0;
> }
> EXPORT_SYMBOL(cros_ec_remove);
> diff --git a/drivers/mfd/cros_ec_i2c.c b/drivers/mfd/cros_ec_i2c.c
> index 9f70de1e4c70..72b0473eb868 100644
> --- a/drivers/mfd/cros_ec_i2c.c
> +++ b/drivers/mfd/cros_ec_i2c.c
> @@ -302,6 +302,7 @@ static int cros_ec_i2c_probe(struct i2c_client *client,
> ec_dev->irq = client->irq;
> ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
> ec_dev->pkt_xfer = cros_ec_pkt_xfer_i2c;
> + ec_dev->xfer_fcn_owner = THIS_MODULE;
> ec_dev->phys_name = client->adapter->name;
> ec_dev->din_size = sizeof(struct ec_host_response_i2c) +
> sizeof(struct ec_response_get_protocol_info);
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/mfd/cros_ec_proto.c
> similarity index 100%
> rename from drivers/platform/chrome/cros_ec_proto.c
> rename to drivers/mfd/cros_ec_proto.c
> diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c
> index 2060d1483043..ce2849790b95 100644
> --- a/drivers/mfd/cros_ec_spi.c
> +++ b/drivers/mfd/cros_ec_spi.c
> @@ -666,6 +666,7 @@ static int cros_ec_spi_probe(struct spi_device *spi)
> ec_dev->irq = spi->irq;
> ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
> ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;
> + ec_dev->xfer_fcn_owner = THIS_MODULE;
> ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
> ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
> sizeof(struct ec_host_response) +
> diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
> index e728a96cabfd..a050c9e8b506 100644
> --- a/drivers/platform/chrome/Kconfig
> +++ b/drivers/platform/chrome/Kconfig
> @@ -65,11 +65,6 @@ config CROS_EC_LPC_MEC
> If you have a ChromeOS Embedded Controller Microchip EC variant
> choose Y here.
>
> -config CROS_EC_PROTO
> - bool
> - help
> - ChromeOS EC communication protocol helpers.
> -
> config CROS_KBD_LED_BACKLIGHT
> tristate "Backlight LED support for Chrome OS keyboards"
> depends on LEDS_CLASS && ACPI
> diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
> index ff3b369911f0..0b5e26ca9c96 100644
> --- a/drivers/platform/chrome/Makefile
> +++ b/drivers/platform/chrome/Makefile
> @@ -8,5 +8,4 @@ obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
> cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
> cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
> obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
> -obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
> obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
> diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
> index 3682e1539251..8f02b188bd3f 100644
> --- a/drivers/platform/chrome/cros_ec_lpc.c
> +++ b/drivers/platform/chrome/cros_ec_lpc.c
> @@ -282,6 +282,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
> ec_dev->phys_name = dev_name(dev);
> ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
> ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
> + ec_dev->xfer_fcn_owner = THIS_MODULE;
> ec_dev->cmd_readmem = cros_ec_lpc_readmem;
> ec_dev->din_size = sizeof(struct ec_host_response) +
> sizeof(struct ec_response_get_protocol_info);
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index 2d4e23c9ea0a..5239107e5091 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -18,6 +18,7 @@
>
> #include <linux/cdev.h>
> #include <linux/device.h>
> +#include <linux/module.h>
> #include <linux/notifier.h>
> #include <linux/mfd/cros_ec_commands.h>
> #include <linux/mutex.h>
> @@ -139,6 +140,7 @@ struct cros_ec_device {
> int dout_size;
> bool wake_enabled;
> bool suspended;
> + struct module *xfer_fcn_owner;
Why do you have to introduce a new property?
Can't you just use THIS_MODULE in try_module_get()?
> int (*cmd_xfer)(struct cros_ec_device *ec,
> struct cros_ec_command *msg);
> int (*pkt_xfer)(struct cros_ec_device *ec,
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
On Sun, Jun 17, 2018 at 11:37 PM Lee Jones <[email protected]> wrote:
>
> On Mon, 04 Jun 2018, Enrico Granata wrote:
>
> > From: Enrico Granata <[email protected]>
> >
> > If one builds the Chrome EC support as modules, there is no explicit
> > dependency chain amongst the several modules (LPC, CHARDEV, CORE, ...)
> >
> > This makes it possible - for instance - to rmmod cros_ec_core, even though
> > cros_ec_dev actively uses it for data transport to the EC chip.
> >
> > This commit makes two changes in an attempt to address this:
> > a) moves cros_ec_proto.c as part of the CORE module; this removes the
> > possibility of unloading cros_ec_core while cros_ec_dev is using it;
> > b) enables cros_ec_core to explicitly register a runtime dependency on
> > the kernel module that is using its cmd and pkt transfer functions
> >
> > Series-to: LKML <[email protected]>
> > Series-cc: [email protected]
> > Signed-off-by: Enrico Granata <[email protected]>
> > ---
> > drivers/mfd/Kconfig | 1 -
> > drivers/mfd/Makefile | 2 +-
> > drivers/mfd/cros_ec.c | 18 ++++++++++++++++--
> > drivers/mfd/cros_ec_i2c.c | 1 +
> > drivers/{platform/chrome => mfd}/cros_ec_proto.c | 0
> > drivers/mfd/cros_ec_spi.c | 1 +
> > drivers/platform/chrome/Kconfig | 5 -----
> > drivers/platform/chrome/Makefile | 1 -
> > drivers/platform/chrome/cros_ec_lpc.c | 1 +
> > include/linux/mfd/cros_ec.h | 2 ++
> > 10 files changed, 22 insertions(+), 10 deletions(-)
> > rename drivers/{platform/chrome => mfd}/cros_ec_proto.c (100%)
> >
> > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > index b860eb5aa194..a8daa2072ae6 100644
> > --- a/drivers/mfd/Kconfig
> > +++ b/drivers/mfd/Kconfig
> > @@ -194,7 +194,6 @@ config MFD_CROS_EC
> > tristate "ChromeOS Embedded Controller"
> > select MFD_CORE
> > select CHROME_PLATFORMS
> > - select CROS_EC_PROTO
> > depends on X86 || ARM || ARM64 || COMPILE_TEST
> > help
> > If you say Y here you get support for the ChromeOS Embedded
> > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > index d9d2cf0d32ef..20537bd27695 100644
> > --- a/drivers/mfd/Makefile
> > +++ b/drivers/mfd/Makefile
> > @@ -12,7 +12,7 @@ obj-$(CONFIG_MFD_SM501) += sm501.o
> > obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o
> > obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
> > obj-$(CONFIG_MFD_BD9571MWV) += bd9571mwv.o
> > -cros_ec_core-objs := cros_ec.o
> > +cros_ec_core-objs := cros_ec.o cros_ec_proto.o
> > cros_ec_core-$(CONFIG_ACPI) += cros_ec_acpi_gpe.o
> > obj-$(CONFIG_MFD_CROS_EC) += cros_ec_core.o
> > obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
> > diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> > index d61024141e2b..9660dc0fc079 100644
> > --- a/drivers/mfd/cros_ec.c
> > +++ b/drivers/mfd/cros_ec.c
> > @@ -168,8 +168,19 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> > */
> > err = cros_ec_sleep_event(ec_dev, 0);
> > if (err < 0)
> > - dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
> > - err);
> > + dev_dbg(dev, "Error %d clearing sleep event to ec", err);
>
> This change is unrelated to the patch.
>
> > + if (ec_dev->xfer_fcn_owner != NULL) {
>
> if (ec_dev->xfer_fcn_owner) ?
>
> > + err = try_module_get(ec_dev->xfer_fcn_owner);
> > + if (err < 0) {
>
> This logic is wrong. try_module_get() returns a bool.
I do not think this is needed at all: the transport drivers (i2c, api)
are using cros_ec_register() provided by cros_ec core, which should
bump up refcount on cros_ec core module preventing it from unloading.
And unloading transport driver should unregister EC instance, stopping
IO.
If cros_ec_dev is not prepared to handle "dead" devices - it is issue
for cros_ec_dev to solve. By the way, it is not solvable my
disallowing module unloading: one can always tear down a device by
manually unbinding driver via sysfs.
Thanks.
--
Dmitry