kernel.git/drivers/tty/serial/samsung.c, branch linux-4.17.y

serial: samsung: fix maxburst parameter for DMA transactions

2018-06-16T07:18:22Z

commit aa2f80e752c75e593b3820f42c416ed9458fa73e upstream. The best granularity of residue that DMA engine can report is in the BURST units, so the serial driver must use MAXBURST = 1 and DMA_SLAVE_BUSWIDTH_1_BYTE if it relies on exact number of bytes transferred by DMA engine. Fixes: 62c37eedb74c ("serial: samsung: add dma reqest/release functions") Signed-off-by: Marek Szyprowski Acked-by: Krzysztof Kozlowski Cc: stable Signed-off-by: Greg Kroah-Hartman

serial: samsung: Fix out-of-bounds access through serial port index

2018-02-28T14:30:00Z

The s3c24xx_serial_ports[] array is indexed using a value derived from the "serialN" alias in DT, or from an incrementing probe index, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_SAMSUNG_UARTS), so this can even be triggered using a legitimate DTB or legitimate board code. Fixes: 13a9f6c64fdc55eb ("serial: samsung: Consider DT alias when probing ports") Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

tty: serial: Remove redundant license text

2017-11-08T12:08:12Z

Now that the SPDX tag is in all tty files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Jiri Slaby Cc: Eric Anholt Cc: Stefan Wahren Cc: Florian Fainelli Cc: Ray Jui Cc: Scott Branden Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Joachim Eastwood Cc: Matthias Brugger Cc: Masahiro Yamada Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Richard Genoud Cc: Alexander Shiyan Cc: Baruch Siach Cc: Pat Gefre Cc: "Guilherme G. Piccoli" Cc: Jason Wessel Cc: Vladimir Zapolskiy Cc: Sylvain Lemieux Cc: Carlo Caione Cc: Kevin Hilman Cc: Liviu Dudau Cc: Sudeep Holla Cc: Lorenzo Pieralisi Cc: Andy Gross Cc: David Brown Cc: "Andreas Färber" Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Kevin Cernekee Cc: Laxman Dewangan Cc: Thierry Reding Cc: Jonathan Hunter Cc: Barry Song Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: Chris Metcalf Cc: Peter Korsgaard Cc: Timur Tabi Cc: Tony Prisk Cc: Michal Simek Cc: "Sören Brinkmann" Signed-off-by: Greg Kroah-Hartman

tty: add SPDX identifiers to all remaining files in drivers/tty/

2017-11-08T12:08:12Z

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Chris Metcalf Cc: Jiri Kosina Cc: David Sterba Cc: James Hogan Cc: Rob Herring Cc: Eric Anholt Cc: Stefan Wahren Cc: Florian Fainelli Cc: Ray Jui Cc: Scott Branden Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Joachim Eastwood Cc: Matthias Brugger Cc: Masahiro Yamada Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Richard Genoud Cc: Alexander Shiyan Cc: Baruch Siach Cc: "Maciej W. Rozycki" Cc: "Uwe Kleine-König" Cc: Pat Gefre Cc: "Guilherme G. Piccoli" Cc: Jason Wessel Cc: Vladimir Zapolskiy Cc: Sylvain Lemieux Cc: Carlo Caione Cc: Kevin Hilman Cc: Liviu Dudau Cc: Sudeep Holla Cc: Lorenzo Pieralisi Cc: Andy Gross Cc: David Brown Cc: "Andreas Färber" Cc: Kevin Cernekee Cc: Laxman Dewangan Cc: Thierry Reding Cc: Jonathan Hunter Cc: Barry Song Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: "David S. Miller" Cc: Peter Korsgaard Cc: Timur Tabi Cc: Tony Prisk Cc: Michal Simek Cc: "Sören Brinkmann" Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Jiri Slaby Signed-off-by: Greg Kroah-Hartman

serial: samsung: Remove useless spinlock

2017-04-08T16:58:52Z

Spinlock taken only for dma_map_single() for TX buffer is completely useless and doesn't protect anything, so remove it to simplify the code. Signed-off-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski Signed-off-by: Greg Kroah-Hartman

serial: samsung: Add missing checks for dma_map_single failure

2017-04-08T16:58:52Z

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") CC: stable@vger.kernel.org # v4.10+ 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

2017-04-08T16:58:52Z

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") CC: stable@vger.kernel.org # v4.0+ 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