| Message ID | 1519324923-196857-3-git-send-email-john.garry@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Fri, 2018-02-23 at 02:42 +0800, John Garry wrote: > It would be useful to make this driver support some > 8250-compatible devices which have no interrupt line. > > For these, we allow for no interrupt, and will fallback on > polling mode. > > Note: the 8250 dt bindings state that "interrupts" > is a required property: > "interrupts : should contain uart interrupt." > > But the 8250_of.c driver can live without it. So > this patch is going this way also. It should be documented in the binding. > if (irq < 0) { > - if (irq != -EPROBE_DEFER) > - dev_err(dev, "cannot get irq\n"); > - return irq; > + if (irq == -EPROBE_DEFER) > + return irq; > + dev_warn(dev, "cannot get irq, using polling > mode\n"); > + irq = 0; NO_IRQ _is_ 0. You need to do something like if (irq < 0) } ... leave existing code ... } if (!irq) dev_warn(, "Use polling mode\n"); -- Andy Shevchenko <andriy.shevchenko@linux.intel.com> Intel Finland Oy -- 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
On 23/02/2018 17:35, Andy Shevchenko wrote: > On Fri, 2018-02-23 at 02:42 +0800, John Garry wrote: >> It would be useful to make this driver support some >> 8250-compatible devices which have no interrupt line. >> >> For these, we allow for no interrupt, and will fallback on >> polling mode. >> >> Note: the 8250 dt bindings state that "interrupts" >> is a required property: >> "interrupts : should contain uart interrupt." >> >> But the 8250_of.c driver can live without it. So >> this patch is going this way also. > > It should be documented in the binding. Agreed. I find the wording a bit ambigious in bindings/serial/8250.txt and snps-dw-apb-uart.txt: Required properties: [...] - interrupts : should contain uart interrupt. It uses the word "should", and not "must". Maybe "should" means "must"... > >> if (irq < 0) { >> - if (irq != -EPROBE_DEFER) >> - dev_err(dev, "cannot get irq\n"); >> - return irq; >> + if (irq == -EPROBE_DEFER) >> + return irq; >> + dev_warn(dev, "cannot get irq, using polling >> mode\n"); >> + irq = 0; > > NO_IRQ _is_ 0. You need to do something like > > if (irq < 0) } > ... leave existing code ... > } > > if (!irq) > dev_warn(, "Use polling mode\n"); OK > Thanks, John -- 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 28fbc8f..3154988 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -422,9 +422,10 @@ static int dw8250_probe(struct platform_device *pdev) } if (irq < 0) { - if (irq != -EPROBE_DEFER) - dev_err(dev, "cannot get irq\n"); - return irq; + if (irq == -EPROBE_DEFER) + return irq; + dev_warn(dev, "cannot get irq, using polling mode\n"); + irq = 0; } spin_lock_init(&p->lock);
It would be useful to make this driver support some 8250-compatible devices which have no interrupt line. For these, we allow for no interrupt, and will fallback on polling mode. Note: the 8250 dt bindings state that "interrupts" is a required property: "interrupts : should contain uart interrupt." But the 8250_of.c driver can live without it. So this patch is going this way also. Signed-off-by: John Garry <john.garry@huawei.com> --- drivers/tty/serial/8250/8250_dw.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) -- 1.9.1 -- 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