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

tty: serial: imx: keep console clocks always on

2020-11-24T12:03:06+00:00

commit e67c139c488e84e7eae6c333231e791f0e89b3fb upstream. For below code, there has chance to cause deadlock in SMP system: Thread 1: clk_enable_lock(); pr_info("debug message"); clk_enable_unlock(); Thread 2: imx_uart_console_write() clk_enable() clk_enable_lock(); Thread 1: Acuired clk enable_lock -> printk -> console_trylock_spinning Thread 2: console_unlock() -> imx_uart_console_write -> clk_disable -> Acquite clk enable_lock So the patch is to keep console port clocks always on like other console drivers. Fixes: 1cf93e0d5488 ("serial: imx: remove the uart_console() check") Acked-by: Uwe Kleine-König Signed-off-by: Fugang Duan Link: https://lore.kernel.org/r/20201111025136.29818-1-fugang.duan@nxp.com Cc: stable [fix up build warning - gregkh] Signed-off-by: Greg Kroah-Hartman

tty: serial: imx: setup the correct sg entry for tx dma

2020-02-28T14:42:48+00:00

commit f76707831829530ffdd3888bebc108aecefccaa0 upstream. There has oops as below happen on i.MX8MP EVK platform that has 6G bytes DDR memory. when (xmit->tail < xmit->head) && (xmit->head == 0), it setups one sg entry with sg->length is zero: sg_set_buf(sgl + 1, xmit->buf, xmit->head); if xmit->buf is allocated from >4G address space, and SDMA only support <4G address space, then dma_map_sg() will call swiotlb_map() to do bounce buffer copying and mapping. But swiotlb_map() don't allow sg entry's length is zero, otherwise report BUG_ON(). So the patch is to correct the tx DMA scatter list. Oops: [ 287.675715] kernel BUG at kernel/dma/swiotlb.c:497! [ 287.680592] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 287.686075] Modules linked in: [ 287.689133] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.3-00016-g3fdc4e0-dirty #10 [ 287.696872] Hardware name: FSL i.MX8MP EVK (DT) [ 287.701402] pstate: 80000085 (Nzcv daIf -PAN -UAO) [ 287.706199] pc : swiotlb_tbl_map_single+0x1fc/0x310 [ 287.711076] lr : swiotlb_map+0x60/0x148 [ 287.714909] sp : ffff800010003c00 [ 287.718221] x29: ffff800010003c00 x28: 0000000000000000 [ 287.723533] x27: 0000000000000040 x26: ffff800011ae0000 [ 287.728844] x25: ffff800011ae09f8 x24: 0000000000000000 [ 287.734155] x23: 00000001b7af9000 x22: 0000000000000000 [ 287.739465] x21: ffff000176409c10 x20: 00000000001f7ffe [ 287.744776] x19: ffff000176409c10 x18: 000000000000002e [ 287.750087] x17: 0000000000000000 x16: 0000000000000000 [ 287.755397] x15: 0000000000000000 x14: 0000000000000000 [ 287.760707] x13: ffff00017f334000 x12: 0000000000000001 [ 287.766018] x11: 00000000001fffff x10: 0000000000000000 [ 287.771328] x9 : 0000000000000003 x8 : 0000000000000000 [ 287.776638] x7 : 0000000000000000 x6 : 0000000000000000 [ 287.781949] x5 : 0000000000200000 x4 : 0000000000000000 [ 287.787259] x3 : 0000000000000001 x2 : 00000001b7af9000 [ 287.792570] x1 : 00000000fbfff000 x0 : 0000000000000000 [ 287.797881] Call trace: [ 287.800328] swiotlb_tbl_map_single+0x1fc/0x310 [ 287.804859] swiotlb_map+0x60/0x148 [ 287.808347] dma_direct_map_page+0xf0/0x130 [ 287.812530] dma_direct_map_sg+0x78/0xe0 [ 287.816453] imx_uart_dma_tx+0x134/0x2f8 [ 287.820374] imx_uart_dma_tx_callback+0xd8/0x168 [ 287.824992] vchan_complete+0x194/0x200 [ 287.828828] tasklet_action_common.isra.0+0x154/0x1a0 [ 287.833879] tasklet_action+0x24/0x30 [ 287.837540] __do_softirq+0x120/0x23c [ 287.841202] irq_exit+0xb8/0xd8 [ 287.844343] __handle_domain_irq+0x64/0xb8 [ 287.848438] gic_handle_irq+0x5c/0x148 [ 287.852185] el1_irq+0xb8/0x180 [ 287.855327] cpuidle_enter_state+0x84/0x360 [ 287.859508] cpuidle_enter+0x34/0x48 [ 287.863083] call_cpuidle+0x18/0x38 [ 287.866571] do_idle+0x1e0/0x280 [ 287.869798] cpu_startup_entry+0x20/0x40 [ 287.873721] rest_init+0xd4/0xe0 [ 287.876949] arch_call_rest_init+0xc/0x14 [ 287.880958] start_kernel+0x420/0x44c [ 287.884622] Code: 9124c021 9417aff8 a94363f7 17ffffd5 (d4210000) [ 287.890718] ---[ end trace 5bc44c4ab6b009ce ]--- [ 287.895334] Kernel panic - not syncing: Fatal exception in interrupt [ 287.901686] SMP: stopping secondary CPUs [ 288.905607] SMP: failed to stop secondary CPUs 0-1 [ 288.910395] Kernel Offset: disabled [ 288.913882] CPU features: 0x0002,2000200c [ 288.917888] Memory Limit: none [ 288.920944] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Reported-by: Eagle Zhou Tested-by: Eagle Zhou Signed-off-by: Fugang Duan Cc: stable Fixes: 7942f8577f2a ("serial: imx: TX DMA: clean up sg initialization") Reviewed-by: Uwe Kleine-König Link: https://lore.kernel.org/r/1581401761-6378-1-git-send-email-fugang.duan@nxp.com Signed-off-by: Greg Kroah-Hartman

tty: serial: imx: use the sg count from dma_map_sg

2020-01-23T07:19:36+00:00

commit 596fd8dffb745afcebc0ec6968e17fe29f02044c upstream. The dmaengine_prep_slave_sg needs to use sg count returned by dma_map_sg, not use sport->dma_tx_nents, because the return value of dma_map_sg is not always same with "nents". Fixes: b4cdc8f61beb ("serial: imx: add DMA support for imx6q") Signed-off-by: Peng Fan Link: https://lore.kernel.org/r/1573108875-26530-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman

serial: imx: fix error handling in console_setup

2019-12-21T09:41:10+00:00

[ Upstream commit 63fd4b94b948c14eeb27a3bbf50ea0f7f0593bad ] The ipg clock only needs to be unprepared in case preparing per clock fails. The ipg clock has already disabled at the point. Fixes: 1cf93e0d5488 ("serial: imx: remove the uart_console() check") Signed-off-by: Stefan Agner Reviewed-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: imx: restore handshaking irq for imx1

2018-10-04T00:01:51+00:00

commit 7e620984b62532783912312e334f3c48cdacbd5d upstream. Back in 2015 when irda was dropped from the driver imx1 was broken. This change reintroduces the support for the third interrupt of the UART. Fixes: afe9cbb1a6ad ("serial: imx: drop support for IRDA") Cc: stable Signed-off-by: Uwe Kleine-König Reviewed-by: Leonard Crestez Signed-off-by: Greg Kroah-Hartman

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

2018-05-25T14:13:14+00:00

[ Upstream commit 5673444821406dda5fc25e4b52aca419f8065a19 ] The imx_ports[] array is indexed using a value derived from the "serialN" alias in DT, or from platform data, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: ff05967a07225ab6 ("serial/imx: add of_alias_get_id() reference back") Signed-off-by: Geert Uytterhoeven Reviewed-by: Uwe Kleine-König Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

serial: imx: ensure UCR3 and UFCR are setup correctly

2018-05-09T07:50:19+00:00

commit 6df765dca378bddf994cfd2044acafa501bd800f upstream. Commit e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off") has a flaw: While UCR3 and UFCR were modified using read-modify-write before it switched to write register values independent of the previous state. That's a good idea in principle (and that's why I did it) but needs more care. This patch reinstates read-modify-write for UFCR and for UCR3 ensures that RXDMUXSEL and ADNIMP are set for post imx1. Fixes: e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off") Signed-off-by: Uwe Kleine-König Acked-by: Mika Penttilä Tested-by: Mika Penttilä Acked-by: Steve Twiss Tested-by: Steve Twiss Cc: Chris Ruehl Signed-off-by: Greg Kroah-Hartman

serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off

2018-03-22T08:17:49+00:00

[ Upstream commit e61c38d85b7392e033ee03bca46f1d6006156175 ] If the UART is operated in DTE mode and UCR3_DCD or UCR3_RI are 1 (which is the reset default) and the opposite side pulls the respective line to its active level the irq triggers after it is requested in .probe. These irqs were already disabled in .startup but this might be too late. Also setup of the UFCR_DCEDTE bit (currently done in .set_termios) is done very late which is critical as it also controls direction of some pins. So setup UFCR_DCEDTE earlier (in .probe) and also disable the broken irqs in DTE mode there before requesting irqs. Acked-by: Lucas Stach Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTS

2018-02-03T16:05:43+00:00

commit 38b1f0fb42f772b8c9aac53593883a18ff5eb9d7 upstream. The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS lines, so only allow such wakeup method when the system actually has RTS/CTS support. Fixes: bc85734b126f ("serial: imx: allow waking up on RTSD") Signed-off-by: Fabio Estevam Reviewed-by: Martin Kaiser Acked-by: Fugang Duan Signed-off-by: Greg Kroah-Hartman

serial: imx: Fix DCD reading

2016-09-27T10:55:27+00:00

The USR2_DCDIN bit is tested for in register usr1. As the name suggests the usr2 register should be used instead. This fixes reading the Carrier detect status. Signed-off-by: Sascha Hauer Fixes: 90ebc4838666 ("serial: imx: repair and complete handshaking") Acked-by: Uwe Kleine-König Cc: # 4.5+ Reviewed-by: Fabio Estevam Signed-off-by: Greg Kroah-Hartman