kernel/linux.git/drivers/tty/serial/samsung.c, branch linux-4.4.y

tty: serial: samsung: Correct clock selection logic

2020-10-01T09:11:55+00:00

[ Upstream commit 7d31676a8d91dd18e08853efd1cb26961a38c6a6 ] Some variants of the samsung tty driver can pick which clock to use for their baud rate generation. In the DT conversion, a default clock was selected to be used if a specific one wasn't assigned and then a comparison of which clock rate worked better was done. Unfortunately, the comparison was implemented in such a way that only the default clock was ever actually compared. Fix this by iterating through all possible clocks, except when a specific clock has already been picked via clk_sel (which is only possible via board files). Signed-off-by: Jonathan Bakker Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/BN6PR04MB06604E63833EA41837EBF77BA3A30@BN6PR04MB0660.namprd04.prod.outlook.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: samsung: Removes the IRQ not found warning

2020-09-03T09:19:26+00:00

commit 8c6c378b0cbe0c9f1390986b5f8ffb5f6ff7593b upstream. In few older Samsung SoCs like s3c2410, s3c2412 and s3c2440, UART IP is having 2 interrupt lines. However, in other SoCs like s3c6400, s5pv210, exynos5433, and exynos4210 UART is having only 1 interrupt line. Due to this, "platform_get_irq(platdev, 1)" call in the driver gives the following false-positive error: "IRQ index 1 not found" on newer SoC's. This patch adds the condition to check for Tx interrupt only for the those SoC's which have 2 interrupt lines. Tested-by: Alim Akhtar Tested-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski Reviewed-by: Alim Akhtar Signed-off-by: Tamseel Shams Cc: stable Link: https://lore.kernel.org/r/20200810030021.45348-1-m.shams@samsung.com Signed-off-by: Greg Kroah-Hartman

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

2020-05-10T08:26:02+00:00

commit 926b7b5122c96e1f18cd20e85a286c7ec8d18c97 upstream. 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

tty: serial: samsung: Properly set flags in autoCTS mode

2019-02-20T09:13:10+00:00

[ Upstream commit 31e933645742ee6719d37573a27cce0761dcf92b ] Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support") has changed the way the autoCTS mode is handled. According to that change, serial drivers which enable H/W autoCTS mode must set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling TX. This patch adds proper handling of UPSTAT_AUTOCTS flag. Signed-off-by: Beomho Seo [mszyprow: rephrased commit message] Signed-off-by: Marek Szyprowski Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: samsung: fix maxburst parameter for DMA transactions

2018-06-16T07:54:26+00:00

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

2018-05-30T05:49:15+00:00

[ Upstream commit 49ee23b71877831ac087d6083f6f397dc19c9664 ] 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: Sasha Levin Signed-off-by: Greg Kroah-Hartman

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

2017-05-20T12:27:02+00:00

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

2017-03-18T11:09:58+00:00

commit f98c7bce570bdbe344b74ff5daa7dfeef3f22929 upstream. 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") Signed-off-by: Krzysztof Kozlowski Signed-off-by: Greg Kroah-Hartman

serial: samsung: Fix ERR pointer dereference on deferred probe

2016-08-20T16:09:17+00:00

commit e51e4d8a185de90424b03f30181b35f29c46a25a upstream. 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") 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()

2016-06-01T19:15:53+00:00

commit b8995f527aac143e83d3900ff39357651ea4e0f6 upstream. 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 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Krzysztof Kozlowski