Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758153AbcJaDIA (ORCPT ); Sun, 30 Oct 2016 23:08:00 -0400 Received: from kvm5.telegraphics.com.au ([98.124.60.144]:36444 "EHLO kvm5.telegraphics.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758045AbcJaDH5 (ORCPT ); Sun, 30 Oct 2016 23:07:57 -0400 Date: Mon, 31 Oct 2016 14:07:58 +1100 (AEDT) From: Finn Thain To: Ondrej Zary cc: Christoph Hellwig , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] NCR5380: Use probe_irq_*() for IRQ probing In-Reply-To: <1477867203-7480-1-git-send-email-linux@rainbow-software.org> Message-ID: References: <1477867203-7480-1-git-send-email-linux@rainbow-software.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6385 Lines: 197 On Sun, 30 Oct 2016, Ondrej Zary wrote: > Use standard probe_irq_on() and probe_irq_off() functions instead of own > implementation. Thanks for doing this. > This prevents warning messages like this in the kernel log: > genirq: Flags mismatch irq 1. 00000000 (NCR-probe) vs. 00000080 (i8042) > > Move the IRQ trigger code to a separate function so it can be used for > other purposes (testing if the IRQ works). > > Also add missing IRQ reset after probe. > > Signed-off-by: Ondrej Zary > --- > drivers/scsi/NCR5380.c | 72 +++++++++++++++++----------------------------- > drivers/scsi/NCR5380.h | 3 +- > drivers/scsi/g_NCR5380.c | 2 +- > 3 files changed, 29 insertions(+), 48 deletions(-) > > diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c > index d849ffa..01c0027 100644 > --- a/drivers/scsi/NCR5380.c > +++ b/drivers/scsi/NCR5380.c > @@ -351,50 +351,13 @@ static void NCR5380_print_phase(struct Scsi_Host *instance) > } > #endif > > - > -static int probe_irq; > - > -/** > - * probe_intr - helper for IRQ autoprobe > - * @irq: interrupt number > - * @dev_id: unused > - * @regs: unused > - * > - * Set a flag to indicate the IRQ in question was received. This is > - * used by the IRQ probe code. > - */ > - > -static irqreturn_t probe_intr(int irq, void *dev_id) > -{ > - probe_irq = irq; > - return IRQ_HANDLED; > -} > - > -/** > - * NCR5380_probe_irq - find the IRQ of an NCR5380 > - * @instance: NCR5380 controller > - * @possible: bitmask of ISA IRQ lines > - * > - * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ > - * and then looking to see what interrupt actually turned up. > - */ > - > -static int __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance, > - int possible) > +static void NCR5380_trigger_irq(struct Scsi_Host *instance) > { > struct NCR5380_hostdata *hostdata = shost_priv(instance); > - unsigned long timeout; > - int trying_irqs, i, mask; > - > - for (trying_irqs = 0, i = 1, mask = 2; i < 16; ++i, mask <<= 1) > - if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0)) > - trying_irqs |= mask; > - > - timeout = jiffies + msecs_to_jiffies(250); > - probe_irq = NO_IRQ; > + unsigned long timeout = jiffies + msecs_to_jiffies(2500); > > /* > - * A interrupt is triggered whenever BSY = false, SEL = true > + * An interrupt is triggered whenever BSY = false, SEL = true > * and a bit set in the SELECT_ENABLE_REG is asserted on the > * SCSI bus. > * > @@ -402,23 +365,40 @@ static int __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance, > * (I/O, C/D, and MSG) match those in the TCR, so we must reset that > * to zero. > */ > - > NCR5380_write(TARGET_COMMAND_REG, 0); > NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); > NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask); > NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL); > > - while (probe_irq == NO_IRQ && time_before(jiffies, timeout)) > + while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) && > + time_before(jiffies, timeout)) > schedule_timeout_uninterruptible(1); You don't need a 2.5 second timeout here. To raise the interrupt the chip should not need more than a bus settle delay (400ns). Calling msleep(1) should be plenty. Better still, please drop the loop, the delay and the BASR_IRQ test here, and if need be, put the delay in the caller. This routine discards the result of that sequence anyway. > > NCR5380_write(SELECT_ENABLE_REG, 0); > NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); > +} > > - for (i = 1, mask = 2; i < 16; ++i, mask <<= 1) > - if (trying_irqs & mask) > - free_irq(i, NULL); > +/** > + * NCR5380_probe_irq - find the IRQ of an NCR5380 > + * @instance: NCR5380 controller > + * > + * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ > + * and then looking to see what interrupt actually turned up. > + */ > + > +static int NCR5380_probe_irq(struct Scsi_Host *instance) > +{ > + struct NCR5380_hostdata *hostdata = shost_priv(instance); > + int irqs, irq; > + Please rename irqs to irq_mask. Other drivers like tty/cyclades.c begin with, /* forget possible initially masked and pending IRQ */ irq = probe_irq_off(probe_irq_on()); Perhaps we need that here too? > + irqs = probe_irq_on(); You should clear any pending interrupt on the chip before you try to trigger another one. > + NCR5380_trigger_irq(instance); Please do the msleep(1) here. > + irq = probe_irq_off(irqs); > + NCR5380_read(RESET_PARITY_INTERRUPT_REG); > + if (irq < 0) > + irq = 0; Please use NO_IRQ instead of 0. > > - return probe_irq; > + return irq; > } > > /** > diff --git a/drivers/scsi/NCR5380.h b/drivers/scsi/NCR5380.h > index 3c6ce54..b2fca52 100644 > --- a/drivers/scsi/NCR5380.h > +++ b/drivers/scsi/NCR5380.h > @@ -290,7 +290,8 @@ static inline struct scsi_cmnd *NCR5380_to_scmd(struct NCR5380_cmd *ncmd_ptr) > #define NCR5380_dprint_phase(flg, arg) do {} while (0) > #endif > > -static int NCR5380_probe_irq(struct Scsi_Host *instance, int possible); > +static void NCR5380_trigger_irq(struct Scsi_Host *instance); > +static int NCR5380_probe_irq(struct Scsi_Host *instance); > static int NCR5380_init(struct Scsi_Host *instance, int flags); > static int NCR5380_maybe_reset_bus(struct Scsi_Host *); > static void NCR5380_exit(struct Scsi_Host *instance); Please move NCR5380_probe_irq and NCR5380_trigger_irq implementations and prototypes out of the core driver and into g_NCR5380.c. The reason is, ISA cards are probably the only 5380 cards ever likely to need manual IRQ configuration. It would better to have g_NCR5380 support more ISA cards than to add more ISA drivers, therefore this code isn't likely to be needed in the core driver. Thanks. -- > diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c > index 7299ad9..3790ed5 100644 > --- a/drivers/scsi/g_NCR5380.c > +++ b/drivers/scsi/g_NCR5380.c > @@ -265,7 +265,7 @@ static int generic_NCR5380_init_one(struct scsi_host_template *tpnt, > if (irq != IRQ_AUTO) > instance->irq = irq; > else > - instance->irq = NCR5380_probe_irq(instance, 0xffff); > + instance->irq = NCR5380_probe_irq(instance); > > /* Compatibility with documented NCR5380 kernel parameters */ > if (instance->irq == 255) >