linux/drivers/tty/serial/sh-sci.c, branch v5.4

serial: sh-sci: Use platform_get_irq_optional() for optional interrupts

2019-10-04T13:02:28Z

As platform_get_irq() now prints an error when the interrupt does not exist, scary warnings may be printed for optional interrupts: sh-sci e6550000.serial: IRQ index 1 not found sh-sci e6550000.serial: IRQ index 2 not found sh-sci e6550000.serial: IRQ index 3 not found sh-sci e6550000.serial: IRQ index 4 not found sh-sci e6550000.serial: IRQ index 5 not found Fix this by calling platform_get_irq_optional() instead for all but the first interrupts, which are optional. Fixes: 7723f4c5ecdb8d83 ("driver core: platform: Add an error message to platform_get_irq*()") Signed-off-by: Geert Uytterhoeven Reviewed-by: Stephen Boyd Reviewed-by: Yoshihiro Shimoda Tested-by: Yoshihiro Shimoda Link: https://lore.kernel.org/r/20191001180743.1041-1-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Don't check for mctrl_gpio_to_gpiod() returning error

2019-09-04T10:43:54Z

Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init routine"), mctrl_gpio_init() returns failure if the assignment to any member of the gpio array results in an error pointer. Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the !CONFIG_GPIOLIB case. Hence there is no longer a need to check for mctrl_gpio_to_gpiod() returning an error value. A simple NULL check is sufficient. This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20190814092924.13857-4-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Don't check for mctrl_gpio_init() returning -ENOSYS

2019-09-04T10:43:50Z

Now that the mctrl_gpio code returns NULL instead of ERR_PTR(-ENOSYS) if CONFIG_GPIOLIB is disabled, we can safely remove this check. Signed-off-by: Frieder Schrempf Acked-by: Uwe Kleine-Knig Link: https://lore.kernel.org/r/20190802100349.8659-3-frieder.schrempf@kontron.de Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Use DEVICE_ATTR_RW() for rx_fifo_trigger

2019-09-04T10:43:50Z

While commit b6b996b6cdeecf7e ("treewide: Use DEVICE_ATTR_RW") converted the rx_fifo_timeout attribute, it forgot to convert rx_fifo_trigger due to a slightly different function naming. Signed-off-by: Geert Uytterhoeven Reviewed-by: Ulrich Hecht Link: https://lore.kernel.org/r/20190731124555.14349-1-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: use driver core functions, not sysfs ones.

2019-09-04T10:43:49Z

This is a driver, do not call "raw" sysfs functions, instead call driver core ones. Specifically convert the use of sysfs_create_file() and sysfs_remove_file() to use device_create_file() and device_remove_file() Cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Link: https://lore.kernel.org/r/20190704084617.3602-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Terminate TX DMA during buffer flushing

2019-07-03T17:31:30Z

While the .flush_buffer() callback clears sci_port.tx_dma_len since commit 1cf4a7efdc71cab8 ("serial: sh-sci: Fix race condition causing garbage during shutdown"), it does not terminate a transmit DMA operation that may be in progress. Fix this by terminating any pending DMA operations, and resetting the corresponding cookie. Signed-off-by: Geert Uytterhoeven Reviewed-by: Eugeniu Rosca Tested-by: Eugeniu Rosca Link: https://lore.kernel.org/r/20190624123540.20629-3-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix TX DMA buffer flushing and workqueue races

2019-07-03T17:31:30Z

When uart_flush_buffer() is called, the .flush_buffer() callback zeroes the tx_dma_len field. This may race with the work queue function handling transmit DMA requests: 1. If the buffer is flushed before the first DMA API call, dmaengine_prep_slave_single() may be called with a zero length, causing the DMA request to never complete, leading to messages like: rcar-dmac e7300000.dma-controller: Channel Address Error happen and, with debug enabled: sh-sci e6e88000.serial: sci_dma_tx_work_fn: ffff800639b55000: 0...0, cookie 126 and DMA timeouts. 2. If the buffer is flushed after the first DMA API call, but before the second, dma_sync_single_for_device() may be called with a zero length, causing the transmit data not to be flushed to RAM, and leading to stale data being output. Fix this by: 1. Letting sci_dma_tx_work_fn() return immediately if the transmit buffer is empty, 2. Extending the critical section to cover all DMA preparational work, so tx_dma_len stays consistent for all of it, 3. Using local copies of circ_buf.head and circ_buf.tail, to make sure they match the actual operation above. Reported-by: Eugeniu Rosca Suggested-by: Yoshihiro Shimoda Signed-off-by: Geert Uytterhoeven Reviewed-by: Eugeniu Rosca Tested-by: Eugeniu Rosca Link: https://lore.kernel.org/r/20190624123540.20629-2-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: disable DMA for uart_console

2019-05-21T10:18:17Z

As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for console UART"), UART console lines use low-level PIO only access functions which will conflict with use of the line when DMA is enabled, e.g. when the console line is also used for systemd messages. So disable DMA support for UART console lines. Reported-by: Michael Rodin Link: https://patchwork.kernel.org/patch/10929511/ Tested-by: Eugeniu Rosca Reviewed-by: Simon Horman Reviewed-by: Wolfram Sang Reviewed-by: Geert Uytterhoeven Cc: stable@vger.kernel.org Signed-off-by: George G. Davis Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix HSCIF RX sampling point adjustment

2019-04-16T13:24:38Z

The calculation of the sampling point has min() and max() exchanged. Fix this by using the clamp() helper instead. Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment") Signed-off-by: Geert Uytterhoeven Reviewed-by: Ulrich Hecht Reviewed-by: Wolfram Sang Acked-by: Dirk Behme Cc: stable Reviewed-by: Simon Horman Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix HSCIF RX sampling point calculation

2019-04-16T13:24:38Z

There are several issues with the formula used for calculating the deviation from the intended rate: 1. While min_err and last_stop are signed, srr and baud are unsigned. Hence the signed values are promoted to unsigned, which will lead to a bogus value of deviation if min_err is negative, 2. Srr is the register field value, which is one less than the actual sampling rate factor, 3. The divisions do not use rounding. Fix this by casting unsigned variables to int, adding one to srr, and using a single DIV_ROUND_CLOSEST(). Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment") Signed-off-by: Geert Uytterhoeven Reviewed-by: Mukesh Ojha Cc: stable Reviewed-by: Ulrich Hecht Signed-off-by: Greg Kroah-Hartman