On Thu, Jul 06, 2023 at 10:20:59AM -0500, Judith Mendez wrote: > Hi Marc > > On 7/6/23 2:25 AM, Marc Kleine-Budde wrote: > > On 05.07.2023 14:53:56, Judith Mendez wrote: > > > Introduce timer polling method to MCAN since some SoCs may not > > > have M_CAN interrupt routed to A53 Linux and do not have > > > interrupt property in device tree M_CAN node. > > > > > > On AM62x SoC, MCANs on MCU domain do not have hardware interrupt > > > routed to A53 Linux, instead they will use timer polling method. > > > > > > Add an hrtimer to MCAN class device. Each MCAN will have its own > > > hrtimer instantiated if there is no hardware interrupt found in > > > device tree M_CAN node. The timer will generate a software > > > interrupt every 1 ms. In hrtimer callback, we check if there is > > > a transaction pending by reading a register, then process by > > > calling the isr if there is. > > > > > > Tested-by: Hiago De Franco <hiago.franco@xxxxxxxxxxx> # Toradex Verdin AM62 > > > Reviewed-by: Tony Lindgren <tony@xxxxxxxxxxx> > > > Signed-off-by: Judith Mendez <jm@xxxxxx> > > > --- ... > > > diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c > > > index 94dc82644113..76d11ce38220 100644 > > > --- a/drivers/net/can/m_can/m_can_platform.c > > > +++ b/drivers/net/can/m_can/m_can_platform.c > > > @@ -5,6 +5,7 @@ > > > // > > > // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/ > > > +#include <linux/hrtimer.h> > > > #include <linux/phy/phy.h> > > > #include <linux/platform_device.h> > > > @@ -96,12 +97,28 @@ static int m_can_plat_probe(struct platform_device *pdev) > > > goto probe_fail; > > > > Please set "irq" to 0 during declaration. > > During declaration of irq, it is already set to 0: > > int irq, ret = 0; The initialization here applies only to ret. int irq = 0, ret = 0; > > > addr = devm_platform_ioremap_resource_byname(pdev, "m_can"); > > > - irq = platform_get_irq_byname(pdev, "int0"); > > > - if (IS_ERR(addr) || irq < 0) { > > > - ret = -EINVAL; > > > + if (IS_ERR(addr)) { > > > + ret = PTR_ERR(addr); > > > goto probe_fail; > > > } > > > + if (device_property_present(mcan_class->dev, "interrupts") || > > > + device_property_present(mcan_class->dev, "interrupt-names")) { > > > + irq = platform_get_irq_byname(pdev, "int0"); > > > + if (irq == -EPROBE_DEFER) { > > > + ret = -EPROBE_DEFER; > > > + goto probe_fail; > > > + } > > > + if (irq < 0) { > > > + ret = -EINVAL; > > > > Please return the original error value. > > The original value returned is -EINVAL: > > - if (IS_ERR(addr) || irq < 0) { > - ret = -EINVAL; > > Perhaps I am missing something here? if (irq < 0) { ret = irq; ... } And you can also get rid of the explicit test for -EPROBE_DEFER this way simplifying the code. Francesco
