From c7299fea67696db5bd09d924d1f1080d894f92ef Mon Sep 17 00:00:00 2001 From: Saravana Kannan Date: Mon, 26 Apr 2021 16:56:38 -0700 Subject: spi: Fix spi device unregister flow When an SPI device is unregistered, the spi->controller->cleanup() is called in the device's release callback. That's wrong for a couple of reasons: 1. spi_dev_put() can be called before spi_add_device() is called. And it's spi_add_device() that calls spi_setup(). This will cause clean() to get called without the spi device ever being setup. 2. There's no guarantee that the controller's driver would be present by the time the spi device's release function gets called. 3. It also causes "sleeping in atomic context" stack dump[1] when device link deletion code does a put_device() on the spi device. Fix these issues by simply moving the cleanup from the device release callback to the actual spi_unregister_device() function. [1] - https://lore.kernel.org/lkml/CAHp75Vc=FCGcUyS0v6fnxme2YJ+qD+Y-hQDQLa2JhWNON9VmsQ@mail.gmail.com/ Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20210426235638.1285530-1-saravanak@google.com Signed-off-by: Mark Brown --- drivers/spi/spi.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index ba425b9c7700..f9885c096563 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -47,10 +47,6 @@ static void spidev_release(struct device *dev) { struct spi_device *spi = to_spi_device(dev); - /* spi controllers may cleanup for released devices */ - if (spi->controller->cleanup) - spi->controller->cleanup(spi); - spi_controller_put(spi->controller); kfree(spi->driver_override); kfree(spi); @@ -558,6 +554,12 @@ static int spi_dev_check(struct device *dev, void *data) return 0; } +static void spi_cleanup(struct spi_device *spi) +{ + if (spi->controller->cleanup) + spi->controller->cleanup(spi); +} + /** * spi_add_device - Add spi_device allocated with spi_alloc_device * @spi: spi_device to register @@ -622,11 +624,13 @@ int spi_add_device(struct spi_device *spi) /* Device may be bound to an active driver when this returns */ status = device_add(&spi->dev); - if (status < 0) + if (status < 0) { dev_err(dev, "can't add %s, status %d\n", dev_name(&spi->dev), status); - else + spi_cleanup(spi); + } else { dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); + } done: mutex_unlock(&spi_add_lock); @@ -710,6 +714,8 @@ void spi_unregister_device(struct spi_device *spi) if (!spi) return; + spi_cleanup(spi); + if (spi->dev.of_node) { of_node_clear_flag(spi->dev.of_node, OF_POPULATED); of_node_put(spi->dev.of_node); -- cgit v1.2.3 From dc5fa590273890a8541ce6e999d606bfb2d73797 Mon Sep 17 00:00:00 2001 From: Leilk Liu Date: Sat, 8 May 2021 14:02:14 +0800 Subject: spi: take the SPI IO-mutex in the spi_set_cs_timing method this patch takes the io_mutex to prevent an unprotected HW register modification in the set_cs_timing callback. Fixes: 4cea6b8cc34e ("spi: add power control when set_cs_timing") Signed-off-by: Leilk Liu Link: https://lore.kernel.org/r/20210508060214.1485-1-leilk.liu@mediatek.com Signed-off-by: Mark Brown --- drivers/spi/spi.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index f9885c096563..a565e7d6bf3b 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3457,9 +3457,12 @@ int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, if (spi->controller->set_cs_timing && !(spi->cs_gpiod || gpio_is_valid(spi->cs_gpio))) { + mutex_lock(&spi->controller->io_mutex); + if (spi->controller->auto_runtime_pm) { status = pm_runtime_get_sync(parent); if (status < 0) { + mutex_unlock(&spi->controller->io_mutex); pm_runtime_put_noidle(parent); dev_err(&spi->controller->dev, "Failed to power device: %d\n", status); @@ -3470,11 +3473,13 @@ int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, hold, inactive); pm_runtime_mark_last_busy(parent); pm_runtime_put_autosuspend(parent); - return status; } else { - return spi->controller->set_cs_timing(spi, setup, hold, + status = spi->controller->set_cs_timing(spi, setup, hold, inactive); } + + mutex_unlock(&spi->controller->io_mutex); + return status; } if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) || -- cgit v1.2.3 From 6b69546912a57ff8c31061f98e56383cc0beffd3 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 11 May 2021 17:09:12 +0300 Subject: spi: Assume GPIO CS active high in ACPI case Currently GPIO CS handling, when descriptors are in use, doesn't take into consideration that in ACPI case the default polarity is Active High and can't be altered. Instead we have to use the per-chip definition provided by SPISerialBus() resource. Fixes: 766c6b63aa04 ("spi: fix client driver breakages when using GPIO descriptors") Cc: Liguang Zhang Cc: Jay Fang Cc: Sven Van Asbroeck Signed-off-by: Andy Shevchenko Tested-by: Xin Hao Link: https://lore.kernel.org/r/20210511140912.30757-1-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown --- drivers/spi/spi.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a565e7d6bf3b..98048af04abf 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -820,15 +820,29 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force) if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) { if (!(spi->mode & SPI_NO_CS)) { - if (spi->cs_gpiod) - /* polarity handled by gpiolib */ - gpiod_set_value_cansleep(spi->cs_gpiod, activate); - else + if (spi->cs_gpiod) { + /* + * Historically ACPI has no means of the GPIO polarity and + * thus the SPISerialBus() resource defines it on the per-chip + * basis. In order to avoid a chain of negations, the GPIO + * polarity is considered being Active High. Even for the cases + * when _DSD() is involved (in the updated versions of ACPI) + * the GPIO CS polarity must be defined Active High to avoid + * ambiguity. That's why we use enable, that takes SPI_CS_HIGH + * into account. + */ + if (has_acpi_companion(&spi->dev)) + gpiod_set_value_cansleep(spi->cs_gpiod, !enable); + else + /* Polarity handled by GPIO library */ + gpiod_set_value_cansleep(spi->cs_gpiod, activate); + } else { /* * invert the enable line, as active low is * default for SPI. */ gpio_set_value_cansleep(spi->cs_gpio, !enable); + } } /* Some SPI masters need both GPIO CS & slave_select */ if ((spi->controller->flags & SPI_MASTER_GPIO_SS) && -- cgit v1.2.3 From 27e7db56cf3dffd302bd7ddfacb1d405cf671a2a Mon Sep 17 00:00:00 2001 From: Saravana Kannan Date: Wed, 5 May 2021 09:47:34 -0700 Subject: spi: Don't have controller clean up spi device before driver unbind When a spi device is unregistered and triggers a driver unbind, the driver might need to access the spi device. So, don't have the controller clean up the spi device before the driver is unbound. Clean up the spi device after the driver is unbound. Fixes: c7299fea6769 ("spi: Fix spi device unregister flow") Reported-by: Lukas Wunner Signed-off-by: Saravana Kannan Tested-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210505164734.175546-1-saravanak@google.com Signed-off-by: Mark Brown --- drivers/spi/spi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 98048af04abf..e353b7a9e54e 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -714,8 +714,6 @@ void spi_unregister_device(struct spi_device *spi) if (!spi) return; - spi_cleanup(spi); - if (spi->dev.of_node) { of_node_clear_flag(spi->dev.of_node, OF_POPULATED); of_node_put(spi->dev.of_node); @@ -723,7 +721,9 @@ void spi_unregister_device(struct spi_device *spi) if (ACPI_COMPANION(&spi->dev)) acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev)); device_remove_software_node(&spi->dev); - device_unregister(&spi->dev); + device_del(&spi->dev); + spi_cleanup(spi); + put_device(&spi->dev); } EXPORT_SYMBOL_GPL(spi_unregister_device); -- cgit v1.2.3