BMC/Intel-BMC/linux.git/drivers/tty/serial/xilinx_uartps.c, branch dev-4.19

serial: set suppress_bind_attrs flag only if builtin

2019-01-26T08:32:34+00:00

[ Upstream commit 646097940ad35aa2c1f2012af932d55976a9f255 ] When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init). devtmpfs gets killed because we try to remove a file and decrement the wb reference count before the noop_backing_device_info gets initialized. [ 0.332075] Serial: AMBA PL011 UART driver [ 0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1 [ 0.502382] console [ttyAMA0] enabled [ 0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000 [ 0.516053] Mem abort info: [ 0.516222] ESR = 0x96000004 [ 0.516417] Exception class = DABT (current EL), IL = 32 bits [ 0.516641] SET = 0, FnV = 0 [ 0.516826] EA = 0, S1PTW = 0 [ 0.516984] Data abort info: [ 0.517149] ISV = 0, ISS = 0x00000004 [ 0.517339] CM = 0, WnR = 0 [ 0.517553] [0000800074c12000] user address but active_mm is swapper [ 0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 0.518305] Modules linked in: [ 0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82 [ 0.519307] Hardware name: linux,dummy-virt (DT) [ 0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 0.519959] pc : __destroy_inode+0x94/0x2a8 [ 0.520212] lr : __destroy_inode+0x78/0x2a8 [ 0.520401] sp : ffff0000098c3b20 [ 0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714 [ 0.520904] x27: 0000000000002000 x26: 0000000000002000 [ 0.521179] x25: ffff000009583000 x24: 0000000000000000 [ 0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0 [ 0.521737] x21: ffff0000093f9338 x20: 0000000000000000 [ 0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400 [ 0.522376] x17: 0000000000000000 x16: 0000000000000000 [ 0.522727] x15: 0000000000000400 x14: 0000000000000400 [ 0.523068] x13: 0000000000000001 x12: 0000000000000001 [ 0.523421] x11: 0000000000000000 x10: 0000000000000970 [ 0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190 [ 0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88 [ 0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb [ 0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff [ 0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000 [ 0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____)) [ 0.525529] Call trace: [ 0.525806] __destroy_inode+0x94/0x2a8 [ 0.526108] destroy_inode+0x34/0x88 [ 0.526370] evict+0x144/0x1c8 [ 0.526636] iput+0x184/0x230 [ 0.526871] dentry_unlink_inode+0x118/0x130 [ 0.527152] d_delete+0xd8/0xe0 [ 0.527420] vfs_unlink+0x240/0x270 [ 0.527665] handle_remove+0x1d8/0x330 [ 0.527875] devtmpfsd+0x138/0x1c8 [ 0.528085] kthread+0x14c/0x158 [ 0.528291] ret_from_fork+0x10/0x18 [ 0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04) [ 0.529367] ---[ end trace 5a3dee47727f877c ]--- Rework to set suppress_bind_attrs flag to avoid removing the device when CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and xilinx_uartps as well. Co-developed-by: Arnd Bergmann Signed-off-by: Arnd Bergmann Signed-off-by: Anders Roxell Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly

2019-01-09T16:38:46+00:00

commit 260683137ab5276113fc322fdbbc578024185fee upstream. This patch Correct the RX interrupt mask value to handle the RX interrupts properly. Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") Signed-off-by: Nava kishore Manne Cc: stable Signed-off-by: Michal Simek Signed-off-by: Greg Kroah-Hartman

serial: xuartps: remove unnecessary register write

2018-06-28T12:23:44+00:00

This writel writes the exact same value as the previous writel and is thus unnecessary. It accidentally became unnecessary in e3538c37ee38 ("tty: xuartps: Beautify read-modify writes"), but the new behaviour is now expected. Link: https://www.spinics.net/lists/linux-serial/msg23168.html Signed-off-by: Helmut Grohne Signed-off-by: Greg Kroah-Hartman

serial: xuartps: reduce hardware TX race condition

2018-06-28T12:23:44+00:00

After sending data to the uart, the driver was waiting until the TX FIFO was empty (for every single char written). After that, TX was disabled by writing the original TX state to the status register. At that time however, the state machine could still be shifting characters. Not waiting can result in strange hardware states, especially when coupled with calls to cdns_uart_set_termios, whose symptom generally is garbage characters being received from uart or a hang. According to UG585, the TACTIVE bit of the channel status register indicates the shifter operation and we should be waiting for that bit to clear. Sending characters does not require the TX FIFO to be empty, but merely to not be full. So cdns_uart_console_putchar is updated accordingly. During tests with an instrumented kernel and an oscilloscope, we could determine that the chance of a race is reduced by this patch. It is not removed entirely. On the oscilloscope, one can see that disabling the transmitter early can result in the transmission hanging in the middle of a character for a tiny duration. This hiccup is enough to desynchronize with a remote device for a sequence of characters until a data bit doesn't match the start or stop bits anymore. Link: https://www.spinics.net/lists/linux-serial/msg23156.html Link: https://www.spinics.net/lists/linux-serial/msg26139.html Signed-off-by: Helmut Grohne Acked-by: Sören Brinkmann Signed-off-by: Greg Kroah-Hartman

serial: xuartps: fix typo in cdns_uart_startup

2018-06-28T12:23:44+00:00

The bit mask changes in commit 6e14f7c1f2c2 ("tty: xuartps: Improve startup function") doesn't do what the commit message advertises. The original behaviour was clearing the RX_DIS bit, but due to missing ~, that bit is now the only bit kept. Currently, the regression is harmless, because the previous write to the control register sets it to TXRST | RXRST. Thus the RX_DIS bit is previously cleared. The *RST bits are cleared by the hardware, so this commit does not currently change behaviour, but makes future changes less risky. Link: https://www.spinics.net/lists/linux-serial/msg23157.html Signed-off-by: Helmut Grohne Fixes: 6e14f7c1f2c2 ("tty: xuartps: Improve startup function") Reviewed-by: Sören Brinkmann Signed-off-by: Greg Kroah-Hartman

Merge 4.17-rc3 into tty-next

2018-04-30T12:14:55+00:00

We want the tty and serial driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman

serial: uartps: Remove static port array

2018-04-25T12:58:45+00:00

Allocate uart port structure dynamically. Signed-off-by: Michal Simek Reviewed-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

serial: uartps: Move cnds_uart_get_port to probe

2018-04-25T12:58:45+00:00

c&p this function to probe as preparation for removing cdns_uart_port[] static array. Signed-off-by: Michal Simek Reviewed-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

serial: uartps: Use dynamic array for console port

2018-04-25T12:58:45+00:00

Driver console functions are using pointer to static array with fixed size. There can be only one serial console at the time which is found by register_console(). register_console() is filling cons->index to port->line value. Signed-off-by: Michal Simek Reviewed-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

serial: uartps: Remove console_initcall from the driver

2018-04-25T12:58:44+00:00

register_console() is called from uart_add_one_port()->uart_configure_port() that's why register_console() is called twice. This patch remove console_initcall to call register_console() only from one location. Also based on my tests cdns_uart_console_setup() is not called from the first register_console() call. Signed-off-by: Michal Simek Reviewed-by: Alan Cox Signed-off-by: Greg Kroah-Hartman