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

serial: samsung: Add missing checks for dma_map_single failure

2017-05-20T12:49:49Z

commit 500fcc08a32bfd54f11951ba81530775df15c474 upstream. This patch adds missing checks for dma_map_single() failure and proper error reporting. Although this issue was harmless on ARM architecture, it is always good to use the DMA mapping API in a proper way. This patch fixes the following DMA API debug warning: WARNING: CPU: 1 PID: 3785 at lib/dma-debug.c:1171 check_unmap+0x8a0/0xf28 dma-pl330 121a0000.pdma: DMA-API: device driver failed to check map error[device address=0x000000006e0f9000] [size=4096 bytes] [mapped as single] Modules linked in: CPU: 1 PID: 3785 Comm: (agetty) Tainted: G W 4.11.0-rc1-00137-g07ca963-dirty #59 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [] (show_stack) from [] (dump_stack+0x84/0xa0) [] (dump_stack) from [] (__warn+0x14c/0x180) [] (__warn) from [] (warn_slowpath_fmt+0x48/0x50) [] (warn_slowpath_fmt) from [] (check_unmap+0x8a0/0xf28) [] (check_unmap) from [] (debug_dma_unmap_page+0x98/0xc8) [] (debug_dma_unmap_page) from [] (s3c24xx_serial_shutdown+0x314/0x52c) [] (s3c24xx_serial_shutdown) from [] (uart_port_shutdown+0x54/0x88) [] (uart_port_shutdown) from [] (uart_shutdown+0xd4/0x110) [] (uart_shutdown) from [] (uart_hangup+0x9c/0x208) [] (uart_hangup) from [] (__tty_hangup+0x49c/0x634) [] (__tty_hangup) from [] (tty_ioctl+0xc88/0x16e4) [] (tty_ioctl) from [] (do_vfs_ioctl+0xc4/0xd10) [] (do_vfs_ioctl) from [] (SyS_ioctl+0x7c/0x8c) [] (SyS_ioctl) from [] (ret_fast_syscall+0x0/0x3c) Reported-by: Seung-Woo Kim Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions") Signed-off-by: Marek Szyprowski Reviewed-by: Bartlomiej Zolnierkiewicz Reviewed-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

serial: samsung: Use right device for DMA-mapping calls

2017-05-20T12:49:49Z

commit 768d64f491a530062ddad50e016fb27125f8bd7c upstream. Driver should provide its own struct device for all DMA-mapping calls instead of extracting device pointer from DMA engine channel. Although this is harmless from the driver operation perspective on ARM architecture, it is always good to use the DMA mapping API in a proper way. This patch fixes following DMA API debug warning: WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1241 check_sync+0x520/0x9f4 samsung-uart 12c20000.serial: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000006df0f580] [size=64 bytes] Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00137-g07ca963 #51 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [] (show_stack) from [] (dump_stack+0x84/0xa0) [] (dump_stack) from [] (__warn+0x14c/0x180) [] (__warn) from [] (warn_slowpath_fmt+0x48/0x50) [] (warn_slowpath_fmt) from [] (check_sync+0x520/0x9f4) [] (check_sync) from [] (debug_dma_sync_single_for_device+0x88/0xc8) [] (debug_dma_sync_single_for_device) from [] (s3c24xx_serial_start_tx_dma+0x100/0x2f8) [] (s3c24xx_serial_start_tx_dma) from [] (s3c24xx_serial_tx_chars+0x198/0x33c) Reported-by: Seung-Woo Kim Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions") Signed-off-by: Marek Szyprowski Reviewed-by: Bartlomiej Zolnierkiewicz Reviewed-by: Krzysztof Kozlowski Reviewed-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

serial: samsung: Continue to work if DMA request fails

2017-03-07T18:58:37Z

If DMA is not available (even when configured in DeviceTree), the driver will fail the startup procedure thus making serial console not available. For example this causes boot failure on QEMU ARMv7 (Exynos4210, SMDKC210): [ 1.302575] OF: amba_device_add() failed (-19) for /amba/pdma@12680000 ... [ 11.435732] samsung-uart 13800000.serial: DMA request failed [ 72.963893] samsung-uart 13800000.serial: DMA request failed [ 73.143361] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000 DMA is not necessary for serial to work, so continue with UART startup after emitting a warning. Fixes: 62c37eedb74c ("serial: samsung: add dma reqest/release functions") Cc: Signed-off-by: Krzysztof Kozlowski Signed-off-by: Greg Kroah-Hartman

serial: samsung: enable clock before accessing interrupt mask resister

2017-02-03T09:12:16Z

Ensure that the uart clock is enabled prior to writing to the interrupt mask register in s3c24xx_serial_resume_noirq function. Without enabing the uart clock, the uart register cannot be accessed. Signed-off-by: Youngmin Nam Signed-off-by: Greg Kroah-Hartman

serial: samsung: Simplify DMA engine initialization code

2017-01-12T10:51:24Z

dma_request_slave_channel_compat() requires filter function and mask, which are not needed on device tree based platforms, so simplify the code by calling the more appropriate dma_request_chan() function. This additionally gives us proper error handling, because the new function returns error codes instead of NULL on failure. Signed-off-by: Marek Szyprowski Reviewed-by: Sylwester Nawrocki Signed-off-by: Greg Kroah-Hartman

serial: samsung: Register cpufreq notifier only on S3C24xx

2016-08-31T13:39:58Z

The Samsung serial driver registered for CPU frequency transitions to recalculate its clock when ARM clock frequency changes. This is needed only on S3C24xx platform so limit the ifdef to respective cpufreq driver. On S3C24xx the ratio ratio between frequencies of UART's parent clock (pclk) and ARM's parent clock (fclk) remains fixed. Therefore when ARM clock frequency goes down, the serial is also affected. Suggested-by: Marek Szyprowski Signed-off-by: Krzysztof Kozlowski Signed-off-by: Greg Kroah-Hartman

tty: serial: samsung: add byte-order aware bit functions

2016-06-25T21:04:12Z

This driver makes use of the __set_bit() and __clear_bit() functions. When running under big-endian, these functions don't convert the bit indexes when working with peripheral registers, leading to the incorrect bits being set and cleared when running big-endian. Add two new driver functions for setting and clearing bits that are byte-order aware. Signed-off-by: Matthew Leach Reviewed-by: Krzysztof Kozlowski Signed-off-by: Greg Kroah-Hartman

serial: samsung: Fix possible out of bounds access on non-DT platform

2016-06-25T20:50:53Z

On non-DeviceTree platforms, the index of serial device is a static variable incremented on each probe. It is incremented even if deferred probe happens when getting the clock in s3c24xx_serial_init_port(). This index is used for referencing elements of statically allocated s3c24xx_serial_ports array. In case of re-probe, the index will point outside of this array leading to memory corruption. Increment the index only on successful probe. Reported-by: Bartlomiej Zolnierkiewicz Fixes: b497549a035c ("[ARM] S3C24XX: Split serial driver into core and per-cpu drivers") Signed-off-by: Krzysztof Kozlowski Signed-off-by: Greg Kroah-Hartman

serial: samsung: Fix ERR pointer dereference on deferred probe

2016-06-25T20:50:53Z

When the clk_get() of "uart" clock returns EPROBE_DEFER, the next re-probe finishes with success but uses invalid (ERR_PTR) values. This leads to dereferencing of ERR_PTR stored under ourport->clk: 12c30000.serial: Controller clock not found (...) 12c30000.serial: ttySAC3 at MMIO 0x12c30000 (irq = 61, base_baud = 0) is a S3C6400/10 Unable to handle kernel paging request at virtual address fffffdfb (clk_prepare) from [] (s3c24xx_serial_pm+0x20/0x128) (s3c24xx_serial_pm) from [] (uart_change_pm+0x38/0x40) (uart_change_pm) from [] (uart_add_one_port+0x31c/0x44c) (uart_add_one_port) from [] (s3c24xx_serial_probe+0x2a8/0x418) (s3c24xx_serial_probe) from [] (platform_drv_probe+0x50/0xb0) (platform_drv_probe) from [] (driver_probe_device+0x1f4/0x2b0) (driver_probe_device) from [] (bus_for_each_drv+0x44/0x8c) (bus_for_each_drv) from [] (__device_attach+0x9c/0x100) (__device_attach) from [] (bus_probe_device+0x84/0x8c) (bus_probe_device) from [] (deferred_probe_work_func+0x60/0x8c) (deferred_probe_work_func) from [] (process_one_work+0x120/0x328) (process_one_work) from [] (worker_thread+0x2c/0x4ac) (worker_thread) from [] (kthread+0xd8/0xf4) (kthread) from [] (ret_from_fork+0x14/0x3c) The first unsuccessful clk_get() causes s3c24xx_serial_init_port() to exit with failure but the s3c24xx_uart_port is left half-configured (e.g. port->mapbase is set, clk contains ERR_PTR). On next re-probe, the function s3c24xx_serial_init_port() will exit early with success because of configured port->mapbase and driver will use old values, including the ERR_PTR as clock. Fix this by cleaning the port->mapbase on error path so each re-probe will initialize all of the port settings. Fixes: 60e93575476f ("serial: samsung: enable clock before clearing pending interrupts during init") Cc: Signed-off-by: Krzysztof Kozlowski Reviewed-by: Javier Martinez Canillas Tested-by: Javier Martinez Canillas Tested-by: Kevin Hilman Signed-off-by: Greg Kroah-Hartman

serial: samsung: Reorder the sequence of clock control when call s3c24xx_serial_set_termios()

2016-04-30T16:26:55Z

This patch fixes the broken serial log when changing the clock source of uart device. Before disabling the original clock source, this patch enables the new clock source to protect the clock off state for a split second. Signed-off-by: Chanwoo Choi Reviewed-by: Marek Szyprowski Signed-off-by: Greg Kroah-Hartman