kernel/linux.git/drivers/tty/serial/samsung.c, branch v4.9.331

tty: serial: samsung_tty: set dma burst_size to 1

2022-07-21T18:40:32+00:00

commit f7e35e4bf1e8dc2c8cbd5e0955dc1bd58558dae0 upstream. The src_maxburst and dst_maxburst have been changed to 1 but the settings of the UCON register aren't changed yet. They should be changed as well according to the dmaengine slave config. Fixes: aa2f80e752c7 ("serial: samsung: fix maxburst parameter for DMA transactions") Cc: stable Cc: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski Signed-off-by: Chanho Park Link: https://lore.kernel.org/r/20220627065113.139520-1-chanho61.park@samsung.com Signed-off-by: Greg Kroah-Hartman

serial: samsung_tty: do not unlock port->lock for uart_write_wakeup()

2022-04-20T07:06:43+00:00

[ Upstream commit 988c7c00691008ea1daaa1235680a0da49dab4e8 ] The commit c15c3747ee32 (serial: samsung: fix potential soft lockup during uart write) added an unlock of port->lock before uart_write_wakeup() and a lock after it. It was always problematic to write data from tty_ldisc_ops::write_wakeup and it was even documented that way. We fixed the line disciplines to conform to this recently. So if there is still a missed one, we should fix them instead of this workaround. On the top of that, s3c24xx_serial_tx_dma_complete() in this driver still holds the port->lock while calling uart_write_wakeup(). So revert the wrap added by the commit above. Cc: Thomas Abraham Cc: Kyungmin Park Cc: Hyeonkook Kim Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220308115153.4225-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

tty: serial: samsung: Correct clock selection logic

2020-10-01T18:40:13+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

2020-09-03T09:21:21+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

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

2019-02-12T18:44:55+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

2018-06-16T07:52:34+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

2018-05-25T14:13:14+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

2017-05-20T12:28:41+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

2017-03-18T11:14:33+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: Register cpufreq notifier only on S3C24xx

2016-08-31T13:39:58+00:00

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