Messages in this thread | | | From | Gwendal Grignou <> | Date | Mon, 4 Jun 2018 17:06:50 -0700 | Subject | Re: [PATCH] Cleanup dependency chain for cros_ec modules |
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On Mon, Jun 4, 2018 at 1:22 PM Enrico Granata <egranata@google.com> wrote: > > From: Enrico Granata <egranata@chromium.org> > > 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 <egranata@chromium.org> > --- > > 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 >
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