- 14 Jul, 2022 5 commits
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Doug Berger authored
Commit 9cabe26e ("serial: 8250_bcm7271: UART errors after resuming from S2") prevented an early enabling of RTS during resume, but it did not actively restore the RTS state after resume. Fixes: 9cabe26e ("serial: 8250_bcm7271: UART errors after resuming from S2") Signed-off-by:
Doug Berger <opendmb@gmail.com> Signed-off-by:
Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20220714031316.404918-1-f.fainelli@gmail.comSigned-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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VAMSHI GAJJELA authored
With PSLVERR_RESP_EN parameter set to 1, the device generates an error response when an attempt to read an empty RBR with FIFO enabled. This happens when LCR writes are ignored when UART is busy. dw8250_check_lcr() in retries to update LCR, invokes dw8250_force_idle() to clear and reset FIFO and eventually reads UART_RX causing the error. Avoid this by not reading RBR/UART_RX when no data is available. Reviewed-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
VAMSHI GAJJELA <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20220713131722.2316829-1-vamshigajjela@google.comSigned-off-by:
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Marek Szyprowski authored
S3C2410_UCON is a 32bit register, so it must be read with rd_regl() instead of rd_reg(), otherwise the upper bits will be zeroed. Fix this. Fixes: 72a43046 ("tty: serial: samsung_tty: loopback mode support") Tested-by:
Chanho Park <chanho61.park@samsung.com> Reviewed-by:
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by:
Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20220712140745.30362-1-m.szyprowski@samsung.comSigned-off-by:
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Geert Uytterhoeven authored
The Aspeed Virtual UART is only present on Aspeed BMC platforms. Hence add a dependency on ARCH_ASPEED, to prevent asking the user about this driver when configuring a kernel without Aspeed BMC support. Reviewed-by:
Jeremy Kerr <jk@ozlabs.org> Signed-off-by:
Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/259138c372d433005b4871789ef9ee8d15320307.1657528861.git.geert+renesas@glider.beSigned-off-by:
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Cameron Williams authored
Add support for some of the Brainboxes PCIe (PX) range of serial cards, including the PX-101, PX-235/PX-246, PX-203/PX-257, PX-260/PX-701, PX-310, PX-313, PX-320/PX-324/PX-376/PX-387, PX-335/PX-346, PX-368, PX-420, PX-803 and PX-846. Signed-off-by:
Cameron Williams <cang1@live.co.uk> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/AM5PR0202MB2564669252BDC59BF55A6E87C4879@AM5PR0202MB2564.eurprd02.prod.outlook.comSigned-off-by:
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- 08 Jul, 2022 8 commits
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Daniel Starke authored
gsmld_poll() currently fails to handle the following corner cases correctly: - remote party closed the associated tty Add the missing checks and map those to EPOLLHUP. Reorder the checks to group them by their reaction. Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220707113223.3685-4-daniel.starke@siemens.comSigned-off-by:
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Daniel Starke authored
The current implementation constipates all transmission paths during flow control except for flow control frames. However, these may not be located at the beginning of the transmission queue of the control channel. Ensure that flow control frames in the transmission queue for the control channel are always handled even if constipated by skipping through other messages. Fixes: 0af02167 ("tty: n_gsm: fix deadlock and link starvation in outgoing data path") Signed-off-by:
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Daniel Starke authored
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.3.3 defines the DM response. There exists no DM command. However, the current implementation incorrectly sends DM as command in case of unexpected UIH frames in gsm_queue(). Correct this behavior by always sending DM as response. Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
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Daniel Starke authored
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.7.3 states that the valid range for the maximum number of retransmissions (N2) is from 0 to 255 (both including). gsm_dlci_t1() handles this number incorrectly by performing N2 - 1 retransmission attempts. Setting N2 to zero results in more than 255 retransmission attempts. Fix gsm_dlci_t1() to comply with 3GPP 27.010. Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
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Ilpo Järvinen authored
When DT provides rs485-term, set termination flag as supported. Reviewed-by:
Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by:
Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-3-ilpo.jarvinen@linux.intel.comSigned-off-by:
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Ilpo Järvinen authored
Embed rs485_supported to uart_port to allow serial core to tweak it as needed. Reviewed-by:
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Ilpo Järvinen authored
prom_putchar_wait() inputs both mask and val but the callers always set them to the same value. Thus pass only val. Suggested-by:
Jiri Slaby <jirislaby@kernel.org> Signed-off-by:
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Uwe Kleine-König authored
Some Freescale 8250 implementations have the problem that a single long break results in one irq per character frame time. The code in fsl8250_handle_irq() that is supposed to handle that uses the BI bit in lsr_saved_flags to detect such a situation and then skip the second received character. However it also stores other error bits and so after a single frame error the character received in the next irq handling is passed to the upper layer with a frame error, too. So after a spike on the data line (which is correctly recognized as a frame error) the following valid character is thrown away, because the driver reports a frame error for that one, too. To weaken this problem restrict saving LSR to only the BI bit. Note however that the handling is still broken: - lsr_saved_flags is updated using orig_lsr which is the LSR content for the first received char, but there might be more in the FIFO, so a character is thrown away that is received later and not necessarily the one following the break. - The doubled break might be the 2nd and 3rd char in the FIFO, so the workaround doesn't catch these, because serial8250_rx_chars() doesn't handle the workaround. - lsr_saved_flags might have set UART_LSR_BI at the entry of fsl8250_handle_irq() which doesn't originate from fsl8250_handle_irq()'s "up->lsr_saved_flags |= orig_lsr & UART_LSR_BI;" but from e.g. from serial8250_tx_empty(). - For a long or a short break this isn't about two characters, but more or only a single one. Fixes: 9deaa53a ("serial: add irq handler for Freescale 16550 errata.") Acked-by:
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20220704085119.55900-1-u.kleine-koenig@pengutronix.deSigned-off-by:
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- 01 Jul, 2022 9 commits
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Daniel Starke authored
Within gsm_activate_mux() all timers and locks are initiated before the actual resource for the control channel is allocated. This can lead to race conditions. Allocate the control channel DLCI object first to avoid race conditions. Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
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Daniel Starke authored
The current implementation queues up new control and user packets as needed and processes this queue down to the ldisc in the same code path. That means that the upper and the lower layer are hard coupled in the code. Due to this deadlocks can happen as seen below while transmitting data, especially during ldisc congestion. Furthermore, the data channels starve the control channel on high transmission load on the ldisc. Introduce an additional control channel data queue to prevent timeouts and link hangups during ldisc congestion. This is being processed before the user channel data queue in gsm_data_kick(), i.e. with the highest priority. Put the queue to ldisc data path into a workqueue and trigger it whenever new data has been put into the transmission queue. Change gsm_dlci_data_sweep() accordingly to fill up the transmission queue until TX_THRESH_HI. This solves the locking issue, keeps latency low and provides good performance on high data load. Note that now all packets from a DLCI are removed from the internal queue if the associated DLCI was closed. This ensures that no data is sent by the introduced write task to an already closed DLCI. BUG: spinlock recursion on CPU#0, test_v24_loop/124 lock: serial8250_ports+0x3a8/0x7500, .magic: dead4ead, .owner: test_v24_loop/124, .owner_cpu: 0 CPU: 0 PID: 124 Comm: test_v24_loop Tainted: G O 5.18.0-rc2 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x34/0x44 do_raw_spin_lock+0x76/0xa0 _raw_spin_lock_irqsave+0x72/0x80 uart_write_room+0x3b/0xc0 gsm_data_kick+0x14b/0x240 [n_gsm] gsmld_write_wakeup+0x35/0x70 [n_gsm] tty_wakeup+0x53/0x60 tty_port_default_wakeup+0x1b/0x30 serial8250_tx_chars+0x12f/0x220 serial8250_handle_irq.part.0+0xfe/0x150 serial8250_default_handle_irq+0x48/0x80 serial8250_interrupt+0x56/0xa0 __handle_irq_event_percpu+0x78/0x1f0 handle_irq_event+0x34/0x70 handle_fasteoi_irq+0x90/0x1e0 __common_interrupt+0x69/0x100 common_interrupt+0x48/0xc0 asm_common_interrupt+0x1e/0x40 RIP: 0010:__do_softirq+0x83/0x34e Code: 2a 0a ff 0f b7 ed c7 44 24 10 0a 00 00 00 48 c7 c7 51 2a 64 82 e8 2d e2 d5 ff 65 66 c7 05 83 af 1e 7e 00 00 fb b8 ff ff ff ff <49> c7 c2 40 61 80 82 0f bc c5 41 89 c4 41 83 c4 01 0f 84 e6 00 00 RSP: 0018:ffffc90000003f98 EFLAGS: 00000286 RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff82642a51 RDI: ffffffff825bb5e7 RBP: 0000000000000200 R08: 00000008de3271a8 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000030 R14: 0000000000000000 R15: 0000000000000000 ? __do_softirq+0x73/0x34e irq_exit_rcu+0xb5/0x100 common_interrupt+0xa4/0xc0 </IRQ> <TASK> asm_common_interrupt+0x1e/0x40 RIP: 0010:_raw_spin_unlock_irqrestore+0x2e/0x50 Code: 00 55 48 89 fd 48 83 c7 18 53 48 89 f3 48 8b 74 24 10 e8 85 28 36 ff 48 89 ef e8 cd 58 36 ff 80 e7 02 74 01 fb bf 01 00 00 00 <e8> 3d 97 33 ff 65 8b 05 96 23 2b 7e 85 c0 74 03 5b 5d c3 0f 1f 44 RSP: 0018:ffffc9000020fd08 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000246 RCX: 0000000000000000 RDX: 0000000000000004 RSI: ffffffff8257fd74 RDI: 0000000000000001 RBP: ffff8880057de3a0 R08: 00000008de233000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000100 R14: 0000000000000202 R15: ffff8880057df0b8 ? _raw_spin_unlock_irqrestore+0x23/0x50 gsmtty_write+0x65/0x80 [n_gsm] n_tty_write+0x33f/0x530 ? swake_up_all+0xe0/0xe0 file_tty_write.constprop.0+0x1b1/0x320 ? n_tty_flush_buffer+0xb0/0xb0 new_sync_write+0x10c/0x190 vfs_write+0x282/0x310 ksys_write+0x68/0xe0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f3e5e35c15c Code: 8b 7c 24 08 89 c5 e8 c5 ff ff ff 89 ef 89 44 24 08 e8 58 bc 02 00 8b 44 24 08 48 83 c4 10 5d c3 48 63 ff b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 fd fc 05 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffcee77cd18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ffcee77cd70 RCX: 00007f3e5e35c15c RDX: 0000000000000100 RSI: 00007ffcee77cd90 RDI: 0000000000000003 RBP: 0000000000000100 R08: 0000000000000000 R09: 7efefefefefefeff R10: 00007f3e5e3bddeb R11: 0000000000000246 R12: 00007ffcee77ce8f R13: 0000000000000001 R14: 000056214404e010 R15: 00007ffcee77cd90 </TASK> Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
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Daniel Starke authored
The function may be used by the user directly and also by the n_gsm internal functions. They can lead into a race condition which results in interleaved frames if both are writing at the same time. The receiving side is not able to decode those interleaved frames correctly. Add a lock around the low side tty write to avoid race conditions and frame interleaving between user originated writes and n_gsm writes. Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
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Daniel Starke authored
In the current implementation control packets are re-transmitted even if the control channel closed down during T2. This is wrong. Check whether the control channel is open before re-transmitting any packets. Note that control channel open/close is handled by T1 and not T2 and remains unaffected by this. Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
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Daniel Starke authored
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.4.6.3.6 states that FCoff stops the transmission on all channels except the control channel. This is already implemented in gsm_data_kick(). However, chapter 5.4.8.1 explains that this shall result in the same behavior as software flow control on the ldisc in advanced option mode. That means only flow control frames shall be sent during flow off. The current implementation does not consider this case. Change gsm_data_kick() to send only flow control frames if constipated to abide the standard. gsm_read_ea_val() and gsm_is_flow_ctrl_msg() are introduced as helper functions for this. It is planned to use gsm_read_ea_val() in later code cleanups for other functions, too. Fixes: c01af4fe ("n_gsm : Flow control handling in Mux driver") Signed-off-by:
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Daniel Starke authored
The current implementation does not handle the situation that no data is in the internal queue and needs to be sent out while the user tty fifo is full. Add a timer that moves more data from user tty down to the internal queue which is then serialized on the ldisc. This timer is triggered if no data was moved from a user tty to the internal queue within 10 * T1. Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
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Daniel Starke authored
1) The function drains the fifo for the given user tty/DLCI without considering 'TX_THRESH_HI' and different to gsm_dlci_data_output_framed(), which moves only one packet from the user side to the internal transmission queue. We can only handle one packet at a time here if we want to allow DLCI priority handling in gsm_dlci_data_sweep() to avoid link starvation. 2) Furthermore, the additional header octet from convergence layer type 2 is not counted against MTU. It is part of the UI/UIH frame message which needs to be limited to MTU. Hence, it is wrong not to consider this octet. 3) Finally, the waiting user tty is not informed about freed space in its send queue. Take at most one packet worth of data out of the DLCI fifo to fix 1). Limit the max user data size per packet to MTU - 1 in case of convergence layer type 2 to leave space for the control signal octet which is added in the later part of the function. This fixes 2). Add tty_port_tty_wakeup() to wake up the user tty if new write space has been made available to fix 3). Fixes: 268e526b ("tty/n_gsm: avoid fifo overflow in gsm_dlci_data_output") Signed-off-by:
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Daniel Starke authored
The current implementation registers/deregisters the user ttys at mux attach/detach. That means that the user devices are available before any control channel is open. However, user channel initialization requires an open control channel. Furthermore, the user is not informed if the mux restarts due to configuration changes. Put the registration/deregistration procedure into separate function to improve readability. Move registration to mux activation and deregistration to mux cleanup to keep the user devices only open as long as a control channel exists. The user will be informed via the device driver if the mux was reconfigured in a way that required a mux re-activation. This makes it necessary to add T2 initialization to gsmld_open() for the ldisc open code path (not the reconfiguration code path) to avoid deletion of an uninitialized T2 at mux cleanup. Fixes: d50f6dca ("tty: n_gsm: expose gsmtty device nodes at ldisc open time") Signed-off-by:
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Daniel Starke authored
After setting up the control channel on both sides the responder side may want to open a virtual tty to listen on until the initiator starts an application on a user channel. The current implementation allows the open() but no other operation, like termios. These fail with EINVAL. The responder sided application has no means to detect an open by the initiator sided application this way. And the initiator sided applications usually expect the responder sided application to listen on the user channel upon open. Set the user channel into half-open state on responder side once a user application opens the virtual tty to allow IO operations on it. Furthermore, keep the user channel constipated until the initiator side opens it to give the responder sided application the chance to detect the new connection and to avoid data loss if the responder sided application starts sending before the user channel is open. Fixes: e1eaea46 ("tty: n_gsm line discipline") Signed-off-by:
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- 30 Jun, 2022 10 commits
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Tomer Maimon authored
Add a compatible string for Nuvoton BMC NPCM845 UART. Signed-off-by:
Tomer Maimon <tmaimon77@gmail.com> Acked-by:
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Ilpo Järvinen authored
Place dw8250_serial_out() before dw8250_serial_out38x() so that it can be called from dw8250_serial_out38x() to do the actual write. Signed-off-by:
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Ilpo Järvinen authored
Instead of open-coding, use BIT(), GENMASK(), and FIELD_GET() helpers. Reviewed-by:
Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by:
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Andy Shevchenko authored
Drop CONFIG_PM and CONFIG_PM_SLEEP ifdeffery while converting dw8250_pm_ops to use new PM macros. Since we are using runtime PM, wrap dw8250_pm_ops into pm_ptr(). Reviewed-by:
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Andy Shevchenko authored
For the sake of better maintenance, sort included headers alphabetically. While at it, split the serial group of headers which makes clear the subsystem the driver belongs to. Reviewed-by:
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Michael Walle authored
If the earlycon parameter is given twice, the kernel will spit out a WARN() in register_console() because it was already registered. The non-dt variant setup_earlycon() already handles that gracefully. The dt variant of_setup_earlycon() doesn't. Add the check there and add the -EALREADY handling in early_init_dt_scan_chosen_stdout(). FWIW, this doesn't happen if CONFIG_ACPI_SPCR_TABLE is set. In that case the registration is delayed until after earlycon parameter(s) are parsed. Reviewed-by:
Rob Herring <robh@kernel.org> Signed-off-by:
Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/r/20220628120705.200617-1-michael@walle.ccSigned-off-by:
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Ilpo Järvinen authored
Accessing LSR requires port lock because it mutates lsr_saved_flags in serial_lsr_in(). Fixes: 197eb5c4 ("serial: 8250_dw: Use serial_lsr_in() in dw8250_handle_irq()") Reviewed-by:
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Zhang Jiaming authored
Change 'timeing' to 'timing'. Change 'Characteres' to 'Characters'. Reviewed-by:
Zhang Jiaming <jiaming@nfschina.com> Link: https://lore.kernel.org/r/20220629094411.39066-1-jiaming@nfschina.comSigned-off-by:
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Chanho Park authored
Internal loopback mode can be supported by setting UCON register's Loopback Mode bit. The mode & bit can be supported since s3c2410 and later SoCs. The prefix of LOOPBACK / BIT(5) naming should be also changed to S3C2410_ in order to avoid confusion. Reviewed-by:
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Chanho Park authored
Regarding Exynos Auto v9 SoC, it supports uarts up to 12. However, the maximum number of the ports has been derived from CONFIG_SERIAL_SAMSUNG_UARTS and tightly coupled with the config for previous Samsung SoCs such as s3c24xx and s3c64xx. To overcome this limitation, this changes the usage of the definition to UART_NR which is widely used from other serial drivers. This also defines the value to 12 only for ARM64 SoCs to not affect the change to previous arm32 SoCs. Instead of enumerating all the ports as predefined arrays, this introduces s3c24xx_serial_init_port_default that is initializing the structure as the default value. Reviewed-by:
Hector Martin <marcan@marcan.st> Reviewed-by:
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- 27 Jun, 2022 8 commits
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Ilpo Järvinen authored
Add 9th bit multipoint addressing mode for DW UART. 9th bit addressing can be used only when HW RS485 is available. Updating RAR (receive address register) is bit tricky because busy indication is not be available when DW UART is strictly 16550 compatible, which is the case with the hardware I was testing with. RAR should not be updated while receive is in progress which is now achieved by deasserting RE and waiting for one frame (in case rx would be in progress, the driver seems to have no way of knowing it w/o busy indication). Because of this complexity, it's better to avoid doing it unless really needed. Co-developed-by:
Heikki Krogerus <heikki.krogerus@linux.intel.com> Co-developed-by:
Raymond Tan <raymond.tan@intel.com> Co-developed-by:
Lakshmi Sowjanya <lakshmi.sowjanya.d@intel.com> Signed-off-by:
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Ilpo Järvinen authored
Add support for RS-485 multipoint addressing using 9th bit [*]. The addressing mode is configured through ->rs485_config(). ADDRB in termios indicates 9th bit addressing mode is enabled. In this mode, 9th bit is used to indicate an address (byte) within the communication line. ADDRB can only be enabled/disabled through ->rs485_config() that is also responsible for setting the destination and receiver (filter) addresses. Add traps to detect unwanted changes to struct serial_rs485 layout using static_assert(). [*] Technically, RS485 is just an electronic spec and does not itself specify the 9th bit addressing mode but 9th bit seems at least "semi-standard" way to do addressing with RS485. Signed-off-by:
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Ilpo Järvinen authored
To be able to alter ADDRB within ->rs485_config(), take termios_rwsem before calling ->rs485_config() and pass termios. Signed-off-by:
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Ilpo Järvinen authored
Use 32-bit reads in order to not lose higher bits of DW UART regs. This change does not fix any known issue as the high bits are not used for anything related to 8250 driver (dw8250_readl_ext and dw8250_writel_ext used within the dwlib are already doing readl/writel/ioread32be/iowrite32be anyway). This change is necessary to enables 9th bit address mode. DW UART reports address frames with BIT(8) of LSR. Reviewed-by:
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Ilpo Järvinen authored
Allow drivers to alter LSR save mask. Reviewed-by:
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Ilpo Järvinen authored
DW flags address received as BIT(8) in LSR. In order to not lose that on read, enlarge lsr_saved_flags to u16. Adjust lsr/status variables and related call chains to use u16. Technically, some of these type conversion would not be needed but it doesn't hurt to be consistent. Signed-off-by:
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Ilpo Järvinen authored
Per file BOTH_EMPTY defines are littering our source code here and there. Define once in serial.h and create helper for the check too. Reviewed-by:
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Ilpo Järvinen authored
Both UART_XMIT_SIZE and SERIAL_XMIT_SIZE are defined. Make them all UART_XMIT_SIZE. Reviewed-by:
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