| Message ID | 1459501618-21021-1-git-send-email-wangkefeng.wang@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
On 2016/4/1 17:58, Andy Shevchenko wrote: > On Fri, 2016-04-01 at 17:06 +0800, Kefeng Wang wrote: >> Commit cdcea058e510("serial: 8250_dw: Avoid serial_outx code >> duplicate >> with new dw8250_check_lcr()") introduce a wrong logic when write val >> to >> LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used >> unconditionally. >> >> But for !PORT_OCTEON, we better to use coincident write func. >> >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> >> --- >> >> We met following calltrace twice, if the change is not necessary, >> correct me, >> and any advice will be appreciated, thanks. > > So, does this fix you issue? If it does than perhaps you need to Cc > stable@ and put Fixes tag as well. We only met this issue twice, for now it is ok, and I will do more test with this patch. > >> --- a/drivers/tty/serial/8250/8250_dw.c >> +++ b/drivers/tty/serial/8250/8250_dw.c >> @@ -104,15 +104,16 @@ static void dw8250_check_lcr(struct uart_port >> *p, int value) >> dw8250_force_idle(p); >> >> #ifdef CONFIG_64BIT >> - __raw_writeq(value & 0xff, offset); >> -#else >> + if (p->type == PORT_OCTEON) >> + __raw_writeq(value & 0xff, offset); >> + else >> +#endif > > You may also get rid of this one, like > > if (IS_ENABLED(CONFIG_64BIT) && p->type == PORT_OCTEON) > ... > else if > ... Agree. > >> if (p->iotype == UPIO_MEM32) >> writel(value, offset); >> else if (p->iotype == UPIO_MEM32BE) >> iowrite32be(value, offset); >> else >> writeb(value, offset); >> -#endif >> } >> /* >> * FIXME: this deadlocks if port->lock is already held > -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index a3fb95d..47d1f3e 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -104,15 +104,16 @@ static void dw8250_check_lcr(struct uart_port *p, int value) dw8250_force_idle(p); #ifdef CONFIG_64BIT - __raw_writeq(value & 0xff, offset); -#else + if (p->type == PORT_OCTEON) + __raw_writeq(value & 0xff, offset); + else +#endif if (p->iotype == UPIO_MEM32) writel(value, offset); else if (p->iotype == UPIO_MEM32BE) iowrite32be(value, offset); else writeb(value, offset); -#endif } /* * FIXME: this deadlocks if port->lock is already held
Commit cdcea058e510("serial: 8250_dw: Avoid serial_outx code duplicate with new dw8250_check_lcr()") introduce a wrong logic when write val to LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used unconditionally. But for !PORT_OCTEON, we better to use coincident write func. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- We met following calltrace twice, if the change is not necessary, correct me, and any advice will be appreciated, thanks. 80300000.uart: ttyS0 at MMIO 0x80300000 (irq = 7, base_baud = 12500000) is a 16550A Unable to handle kernel paging request at virtual address ffffff8008e8000c pgd = ffffff8008c14000 [ffffff8008e8000c] *pgd=00000013ffffe003,*pud=00000013ffffe003, *pmd=00000013ee043003, *pte=00e8000080300707 Internal error: Oops: 96000061 [#1] PREEMPT SMP Modules linked in: CPU: 13 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc1+ #51 Hardware name: Huawei Technologies Co., Ltd. D02/D02, BIOS Bios Version 01/01/1900 task: ffffffd3ee358000 ti: ffffffd3ee360000 task.ti:ffffffd3ee360000 PC is at dw8250_check_lcr+0x54/0x98 LR is at dw8250_check_lcr+0x54/0x98 pc : [<ffffff800842f2c4>] lr : [<ffffff800842f2c4>]pstate: 800000c5 sp : ffffffd3ee363740 x29: ffffffd3ee363740 x28: 0000000000000000 x27: ffffff800897d668 x26: ffffffd3ed434100 x25: ffffff80089e89b0 x24: 000000000000006d x23: 0000000000000093 x22: 0000000000000093 x21: ffffff8008e8000c x20: 00000000000003e8 x19: ffffff8008bfde28 x18: 0000000000000006 x17: 0000000000000000 x16: 0000000000000001 x15: 000000000001c200 x14: 0000000000000011 x13: 0000000000000c80 x12: 0000000000000011 x11: ffffff800881c050 x10: 000000000001cb00 x9 : 000000000001cb00 x8 : ffffff800881c050 x7 : 000000000001b900 x6 : 0000000000000020 x5 : ffffffd3ec8d9a18 x4 : ffffff8008e80000 x3 : ffffff8008bfde28 x2 : 000000000000000d x1 : 0000000000000000 x0 : 000000000000000d drivers/tty/serial/8250/8250_dw.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) -- 1.7.12.4 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html