kernel.git/drivers/tty/serial/msm_serial.c, branch linux-4.11.y

tty: serial: msm: Fix module autoload

2017-01-12T10:51:25Z

If the driver is built as a module, autoload won't work because the module alias information is not filled. So user-space can't match the registered device with the corresponding module. Export the module alias information using the MODULE_DEVICE_TABLE() macro. Before this patch: $ modinfo drivers/tty/serial/msm_serial.ko | grep alias $ After this patch: $ modinfo drivers/tty/serial/msm_serial.ko | grep alias alias: of:N*T*Cqcom,msm-uartdmC* alias: of:N*T*Cqcom,msm-uartdm alias: of:N*T*Cqcom,msm-uartC* alias: of:N*T*Cqcom,msm-uart Signed-off-by: Javier Martinez Canillas Acked-by: Bjorn Andersson Cc: stable Signed-off-by: Greg Kroah-Hartman

tty: serial: msm: fix definition of msm_stop_dma

2016-06-25T17:23:54Z

The msm_stop_dma() is not exported from the driver, so make it static to stop the following warning: drivers/tty/serial/msm_serial.c:84:6: warning: symbol 'msm_stop_dma' was not declared. Should it be static? Signed-off-by: Ben Dooks Acked-by: Andy Gross Reviewed-by: Bjorn Andersson Reviewed-by: Stephen Boyd Signed-off-by: Greg Kroah-Hartman

tty: serial: msm: Don't read off end of tx fifo

2016-06-25T17:23:54Z

For dm uarts in pio mode tx data is transferred to the fifo register 4 bytes at a time, but care is not taken when these 4 bytes spans the end of the xmit buffer so the loop might read up to 3 bytes past the buffer and then skip the actual data at the beginning of the buffer. Fix this by, analogous to the DMA case, make sure the chunk doesn't wrap the xmit buffer. Fixes: 3a878c430fd6 ("tty: serial: msm: Add TX DMA support") Cc: Ivan Ivanov Cc: stable@vger.kernel.org Reported-by: Frank Rowand Reported-by: Nicolas Dechesne Signed-off-by: Bjorn Andersson Acked-by: Andy Gross Tested-by: Frank Rowand Reviewed-by: Stephen Boyd Signed-off-by: Greg Kroah-Hartman

tty:serial:msm:Do not restore Rx interrupts in DMA

2016-06-25T17:23:54Z

Avoid data corruption issues that result in CRC errors during file transfers over serial ports at higher baud rates. The current msm_serial driver masks the FIFO Rx interrupts in msm_start_rx_dma() since Rx FIFO interrupts are not required in DMA mode. However, msm_complete_rx_dma() re-enables the Rx FIFO interrupts which could cause RXSTALE event to be processed when a TXLEV interrupt occurs. The following is the sequence of events that could occur resulting in data corruption. msm_start_rx_dma -> msm_complete_rx_dma --> spin_unlock_irqrestore(&port->lock) --> msm_uart_irq()(For TXLEV interrupt) --> msm_handle_rx_dm() (Read from FIFO resulting in data corruption) The patch fixes the issue by not restoring the RXLEV and RXSTALE interrupts in msm_complete_rx_dma(). These interrupts are required only in FIFO mode. Signed-off-by: Charanya Venkatraman Acked-by: Andy Gross Reviewed-by: Stephen Boyd Signed-off-by: Greg Kroah-Hartman

tty: serial: msm: Cleanup include usage

2016-06-25T17:23:54Z

The hrtimer include isn't used and neither is serial. Drop those ones. The irq.h header really should be interrupt.h because this is an interrupt user and not an interrupt chip. Finally add wait.h for the wake_up*() usage in this driver and kernel.h for container_of(). Signed-off-by: Stephen Boyd Acked-by: Andy Gross Signed-off-by: Greg Kroah-Hartman

tty: serial: msm: Only configure MND registers on hw that has it

2016-06-25T17:23:54Z

The registers that msm_serial_set_mnd_regs() writes only exist on the non-uartdm hardware, so let's return early here if this function is called on uartdm hardware. This also prevents us from messing up the uartclk variable if the uartclk rate happens to be 19.2 or 4.8 MHz. Signed-off-by: Stephen Boyd Acked-by: Andy Gross Signed-off-by: Greg Kroah-Hartman

tty: serial: msm: Move header file into driver

2016-06-25T17:23:54Z

This header file is only used by the driver, so let's merge the two together to reduce files and make it easier to see the whole driver without flipping through two files. This also makes it easier to use the structures defined in msm_serial.c in the functions that are defined in msm_serial.h by placing them in the proper locations. Signed-off-by: Stephen Boyd Acked-by: Andy Gross Signed-off-by: Greg Kroah-Hartman

tty: serial: msm: Support more bauds

2016-04-30T16:26:55Z

The msm_find_best_baud() function is written with the assumption that the port->uartclk rate is fixed to a particular rate at boot time, but now this driver changes that clk rate at runtime when the baud is changed. The way the hardware works is that an input clk rate comes from the clk controller into the uart hw block. That rate is typically 1843200 or 3686400 Hz. That rate can then be divided by an internal divider in the hw block to achieve a particular baud on the serial wire. msm_find_best_baud() is looking for that divider value. A few things are wrong with the way the code is written. First, it assumes that the maximum baud that the uart can support if the clk rate is fixed at boot is 460800, which would correspond to an input clk rate of 230400 * 16 == 3686400 Hz. Except some devices have a boot rate of 1843200 Hz or max baud of 115200, so achieving 230400 on those devices doesn't work at all because we don't increase the clk rate unless max baud is 460800. Second, we can't achieve bauds higher than 460800 that require anything besides a divisor of 1, because we always call msm_find_best_baud() with a fixed port->uartclk rate that will eventually be changed after we calculate the divisor. So if we need to get a baud of 500000, we'll just multiply that by 16 and hope that the clk can give us 500000 * 16 == 8000000 Hz, which it typically can't do. To really achieve 500000 baud, we need to get an input clk rate of 24000000 Hz and then divide that by 3 inside the uart hardware. Finally, we return success for bauds even when we can't actually achieve them. This means that when the user asks for 500000 baud, we actually get 921600 right now, but the user doesn't know that. Fix all of this by searching through the divisor and clk rate space with a combination of clk_round_rate() and baud calculations, keeping track of the best clk rate and divisor we find if we can't get an exact match. Typically we can get an exact match with a divisor of 1, but sometimes we need to keep track and try more frequencies. On my msm8916 device, this results in all standard bauds in baud_table being supported except for 1800, 576000, 1152000, and 4000000. Fixes: 850b37a71bde ("tty: serial: msm: Remove 115.2 Kbps maximum baud rate limitation") Cc: "Ivan T. Ivanov" Cc: Matthew McClintock Signed-off-by: Stephen Boyd Tested-by: Srinivas Kandagatla Acked-by: Andy Gross Acked-by: Bjorn Andersson Tested-by: Cristian Prundeanu Signed-off-by: Greg Kroah-Hartman

tty: msm_serial: remove static clk rate setting in probe

2016-04-30T16:26:55Z

The issue with setting up a fixed clock rate at probe is that it would overwrite the console rate set by the bootloader for its console device. This would result in serial out corruption or missing log when we system is booted with earlycon. This is not a issue if we boot system without earlycon. This setup is at least not required with the mainline driver, this code used to be required because the clk_enable() call would fail if clk_set_rate() wasn't called first. Originally the issue was noticed on DB410c which is based on APQ8016 chipset. Without this patch the console log with earlycon would look like: ... [ 0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=64, nr_cpu_ids=1 [ 0.000000] NR_IRQS:64 nr_irqs:64 0 ��+HH��0.699378] console [ttyMSM0] enabled [ 0.699378] console [ttyMSM0] enabled [ 0.702003] bootconsole [uart0] disabled [ 0.702003] bootconsole [uart0] disabled ... with this patch I can see all the skipped lines on the console Reviewed-by: Stephen Boyd Signed-off-by: Srinivas Kandagatla Acked-by: Andy Gross Tested-by: Pramod Gurav Signed-off-by: Greg Kroah-Hartman

earlycon: Use common framework for earlycon declarations

2016-02-07T06:07:37Z

Use a single common table of struct earlycon_id for both command line and devicetree. Re-define OF_EARLYCON_DECLARE() macro to instance a unique earlycon declaration (the declaration is only guaranteed to be unique within a compilation unit; separate compilation units must still use unique earlycon names). The semantics of OF_EARLYCON_DECLARE() is different; it declares an earlycon which can matched either on the command line or by devicetree. EARLYCON_DECLARE() is semantically unchanged; it declares an earlycon which is matched by command line only. Remove redundant instances of EARLYCON_DECLARE(). This enables all earlycons to properly initialize struct console with the appropriate name and index, which improves diagnostics and enables direct earlycon-to-console handoff. Acked-by: Rob Herring Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman