| Message ID | 20191125134551.v2.2.Iddc7dd74f893297cb932e9825d413e7890633b3d@changeid |
|---|---|
| State | Rejected |
| Headers | show |
| Series | Convert cros-ec-i2c-tunnel to MFD Cell | expand |
Hi Raul, On 25/11/19 21:47, Raul E Rangel wrote: > If the i2c-cros-ec-tunnel driver is compiled into the kernel, it is > possible that i2c-cros-ec-tunnel could be probed before cros_ec_XXX > has finished initializing and setting the drvdata. This would cause a > NULL pointer panic. > > Converting this driver over to an MFD solves the problem and aligns with > where the cros_ec is going. > > Signed-off-by: Raul E Rangel <rrangel@chromium.org> > --- > You can now see the device node lives under the mfd device. > > $ find /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/ -iname firmware_node -exec ls -l '{}' \; > /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/firmware_node -> ../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00 > /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/i2c-9/firmware_node -> ../../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00 > /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/i2c-9/i2c-10EC5682:00/firmware_node -> ../../../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00/10EC5682:00 > > Changes in v2: > - Moved i2c tunnel into cros_ec_platform_cells > - Requires https://lkml.org/lkml/2019/11/21/208 to correctly enumerate. > > drivers/i2c/busses/i2c-cros-ec-tunnel.c | 36 +++++++++---------------- > drivers/mfd/cros_ec_dev.c | 9 +++++++ > 2 files changed, 22 insertions(+), 23 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-cros-ec-tunnel.c b/drivers/i2c/busses/i2c-cros-ec-tunnel.c > index 5d91e33eb600..2e3217678fa3 100644 > --- a/drivers/i2c/busses/i2c-cros-ec-tunnel.c > +++ b/drivers/i2c/busses/i2c-cros-ec-tunnel.c > @@ -6,6 +6,7 @@ > #include <linux/acpi.h> > #include <linux/module.h> > #include <linux/i2c.h> > +#include <linux/mfd/cros_ec.h> > #include <linux/platform_data/cros_ec_commands.h> > #include <linux/platform_data/cros_ec_proto.h> > #include <linux/platform_device.h> > @@ -27,7 +28,6 @@ > struct ec_i2c_device { > struct device *dev; > struct i2c_adapter adap; > - struct cros_ec_device *ec; > > u16 remote_bus; > > @@ -176,6 +176,7 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], > { > struct ec_i2c_device *bus = adap->algo_data; > struct device *dev = bus->dev; > + struct cros_ec_dev *ec = dev_get_drvdata(dev->parent); > const u16 bus_num = bus->remote_bus; > int request_len; > int response_len; > @@ -183,6 +184,16 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], > int result; > struct cros_ec_command *msg; > > + if (!ec) { > + dev_err(dev, "%s: ec is missing!\n", __func__); > + return -EINVAL; > + } > + > + if (!ec->ec_dev) { > + dev_err(dev, "%s: ec->ec_dev is missing!\n", __func__); > + return -EINVAL; > + } > + > request_len = ec_i2c_count_message(i2c_msgs, num); > if (request_len < 0) { > dev_warn(dev, "Error constructing message %d\n", request_len); > @@ -212,7 +223,7 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], > msg->outsize = request_len; > msg->insize = response_len; > > - result = cros_ec_cmd_xfer_status(bus->ec, msg); > + result = cros_ec_cmd_xfer_status(ec->ec_dev, msg); > if (result < 0) { > dev_err(dev, "Error transferring EC i2c message %d\n", result); > goto exit; > @@ -241,17 +252,11 @@ static const struct i2c_algorithm ec_i2c_algorithm = { > > static int ec_i2c_probe(struct platform_device *pdev) > { > - struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); > struct device *dev = &pdev->dev; > struct ec_i2c_device *bus = NULL; > u32 remote_bus; > int err; > > - if (!ec->cmd_xfer) { > - dev_err(dev, "Missing sendrecv\n"); > - return -EINVAL; > - } > - > bus = devm_kzalloc(dev, sizeof(*bus), GFP_KERNEL); > if (bus == NULL) > return -ENOMEM; > @@ -263,7 +268,6 @@ static int ec_i2c_probe(struct platform_device *pdev) > } > bus->remote_bus = remote_bus; > > - bus->ec = ec; > bus->dev = dev; > > bus->adap.owner = THIS_MODULE; > @@ -292,25 +296,11 @@ static int ec_i2c_remove(struct platform_device *dev) > return 0; > } > > -static const struct of_device_id cros_ec_i2c_of_match[] = { > - { .compatible = "google,cros-ec-i2c-tunnel" }, > - {}, > -}; > -MODULE_DEVICE_TABLE(of, cros_ec_i2c_of_match); > - > -static const struct acpi_device_id cros_ec_i2c_tunnel_acpi_id[] = { > - { "GOOG0012", 0 }, > - { } > -}; > -MODULE_DEVICE_TABLE(acpi, cros_ec_i2c_tunnel_acpi_id); > - > static struct platform_driver ec_i2c_tunnel_driver = { > .probe = ec_i2c_probe, > .remove = ec_i2c_remove, > .driver = { > .name = "cros-ec-i2c-tunnel", > - .acpi_match_table = ACPI_PTR(cros_ec_i2c_tunnel_acpi_id), > - .of_match_table = of_match_ptr(cros_ec_i2c_of_match), I still think that the tables should be in the i2c-cros-ec-tunnel. > }, > }; > > diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c > index 1efdba18f20b..04f8fc5772f0 100644 > --- a/drivers/mfd/cros_ec_dev.c > +++ b/drivers/mfd/cros_ec_dev.c > @@ -101,12 +101,21 @@ static const struct cros_feature_to_cells cros_subdevices[] = { > }, > }; > > +static const struct mfd_cell_acpi_match cros_ec_i2c_tunnel_acpi_match = { > + .pnpid = "GOOG0012" > +}; > + > static const struct mfd_cell cros_ec_platform_cells[] = { > { .name = "cros-ec-chardev", }, > { .name = "cros-ec-debugfs", }, > { .name = "cros-ec-lightbar", }, > { .name = "cros-ec-pd-sysfs" }, > { .name = "cros-ec-sysfs", }, > + { > + .name = "cros-ec-i2c-tunnel", > + .acpi_match = &cros_ec_i2c_tunnel_acpi_match, > + .of_compatible = "google,cros-ec-i2c-tunnel" > + }, We can't do this. With this change, on OF-based systems, the cros-ec-i2c-tunnel will be instantiated twice. Once because of the mfd_add_device call for the above cells and another one because of the call of of_platform_populate. I think I understand what you are trying to solve, but not convinced about the solution. I think that I can't test for cros-ec-i2c-tunnel case because are no devices out, but should be similar for cros-ec-keyb driver. Let me check if I have an ACPI based device supporting this (Samus is an option, I guess) Thanks, Enric > }; > > static const struct mfd_cell cros_ec_vbc_cells[] = { >
diff --git a/drivers/i2c/busses/i2c-cros-ec-tunnel.c b/drivers/i2c/busses/i2c-cros-ec-tunnel.c index 5d91e33eb600..2e3217678fa3 100644 --- a/drivers/i2c/busses/i2c-cros-ec-tunnel.c +++ b/drivers/i2c/busses/i2c-cros-ec-tunnel.c @@ -6,6 +6,7 @@ #include <linux/acpi.h> #include <linux/module.h> #include <linux/i2c.h> +#include <linux/mfd/cros_ec.h> #include <linux/platform_data/cros_ec_commands.h> #include <linux/platform_data/cros_ec_proto.h> #include <linux/platform_device.h> @@ -27,7 +28,6 @@ struct ec_i2c_device { struct device *dev; struct i2c_adapter adap; - struct cros_ec_device *ec; u16 remote_bus; @@ -176,6 +176,7 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], { struct ec_i2c_device *bus = adap->algo_data; struct device *dev = bus->dev; + struct cros_ec_dev *ec = dev_get_drvdata(dev->parent); const u16 bus_num = bus->remote_bus; int request_len; int response_len; @@ -183,6 +184,16 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], int result; struct cros_ec_command *msg; + if (!ec) { + dev_err(dev, "%s: ec is missing!\n", __func__); + return -EINVAL; + } + + if (!ec->ec_dev) { + dev_err(dev, "%s: ec->ec_dev is missing!\n", __func__); + return -EINVAL; + } + request_len = ec_i2c_count_message(i2c_msgs, num); if (request_len < 0) { dev_warn(dev, "Error constructing message %d\n", request_len); @@ -212,7 +223,7 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], msg->outsize = request_len; msg->insize = response_len; - result = cros_ec_cmd_xfer_status(bus->ec, msg); + result = cros_ec_cmd_xfer_status(ec->ec_dev, msg); if (result < 0) { dev_err(dev, "Error transferring EC i2c message %d\n", result); goto exit; @@ -241,17 +252,11 @@ static const struct i2c_algorithm ec_i2c_algorithm = { static int ec_i2c_probe(struct platform_device *pdev) { - struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); struct device *dev = &pdev->dev; struct ec_i2c_device *bus = NULL; u32 remote_bus; int err; - if (!ec->cmd_xfer) { - dev_err(dev, "Missing sendrecv\n"); - return -EINVAL; - } - bus = devm_kzalloc(dev, sizeof(*bus), GFP_KERNEL); if (bus == NULL) return -ENOMEM; @@ -263,7 +268,6 @@ static int ec_i2c_probe(struct platform_device *pdev) } bus->remote_bus = remote_bus; - bus->ec = ec; bus->dev = dev; bus->adap.owner = THIS_MODULE; @@ -292,25 +296,11 @@ static int ec_i2c_remove(struct platform_device *dev) return 0; } -static const struct of_device_id cros_ec_i2c_of_match[] = { - { .compatible = "google,cros-ec-i2c-tunnel" }, - {}, -}; -MODULE_DEVICE_TABLE(of, cros_ec_i2c_of_match); - -static const struct acpi_device_id cros_ec_i2c_tunnel_acpi_id[] = { - { "GOOG0012", 0 }, - { } -}; -MODULE_DEVICE_TABLE(acpi, cros_ec_i2c_tunnel_acpi_id); - static struct platform_driver ec_i2c_tunnel_driver = { .probe = ec_i2c_probe, .remove = ec_i2c_remove, .driver = { .name = "cros-ec-i2c-tunnel", - .acpi_match_table = ACPI_PTR(cros_ec_i2c_tunnel_acpi_id), - .of_match_table = of_match_ptr(cros_ec_i2c_of_match), }, }; diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c index 1efdba18f20b..04f8fc5772f0 100644 --- a/drivers/mfd/cros_ec_dev.c +++ b/drivers/mfd/cros_ec_dev.c @@ -101,12 +101,21 @@ static const struct cros_feature_to_cells cros_subdevices[] = { }, }; +static const struct mfd_cell_acpi_match cros_ec_i2c_tunnel_acpi_match = { + .pnpid = "GOOG0012" +}; + static const struct mfd_cell cros_ec_platform_cells[] = { { .name = "cros-ec-chardev", }, { .name = "cros-ec-debugfs", }, { .name = "cros-ec-lightbar", }, { .name = "cros-ec-pd-sysfs" }, { .name = "cros-ec-sysfs", }, + { + .name = "cros-ec-i2c-tunnel", + .acpi_match = &cros_ec_i2c_tunnel_acpi_match, + .of_compatible = "google,cros-ec-i2c-tunnel" + }, }; static const struct mfd_cell cros_ec_vbc_cells[] = {
If the i2c-cros-ec-tunnel driver is compiled into the kernel, it is possible that i2c-cros-ec-tunnel could be probed before cros_ec_XXX has finished initializing and setting the drvdata. This would cause a NULL pointer panic. Converting this driver over to an MFD solves the problem and aligns with where the cros_ec is going. Signed-off-by: Raul E Rangel <rrangel@chromium.org> --- You can now see the device node lives under the mfd device. $ find /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/ -iname firmware_node -exec ls -l '{}' \; /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/firmware_node -> ../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00 /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/i2c-9/firmware_node -> ../../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00 /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/i2c-9/i2c-10EC5682:00/firmware_node -> ../../../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00/10EC5682:00 Changes in v2: - Moved i2c tunnel into cros_ec_platform_cells - Requires https://lkml.org/lkml/2019/11/21/208 to correctly enumerate. drivers/i2c/busses/i2c-cros-ec-tunnel.c | 36 +++++++++---------------- drivers/mfd/cros_ec_dev.c | 9 +++++++ 2 files changed, 22 insertions(+), 23 deletions(-)