From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753591AbbKZWdd (ORCPT ); Thu, 26 Nov 2015 17:33:33 -0500 Received: from kvm5.telegraphics.com.au ([98.124.60.144]:43240 "EHLO kvm5.telegraphics.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753549AbbKZWc6 (ORCPT ); Thu, 26 Nov 2015 17:32:58 -0500 Date: Fri, 27 Nov 2015 09:32:46 +1100 (AEDT) From: Finn Thain To: Ondrej Zary cc: "James E.J. Bottomley" , Michael Schmitz , linux-m68k@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 22/71] ncr5380: Eliminate selecting state In-Reply-To: <201511262035.40920.linux@rainbow-software.org> Message-ID: References: <20151118083455.331768508@telegraphics.com.au> <201511252259.26792.linux@rainbow-software.org> <201511262035.40920.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 On Thu, 26 Nov 2015, Ondrej Zary wrote: > > [ 156.014234] scsi host2: Generic NCR5380/NCR53C400 SCSI, io_port 0x0, n_io_port 0, base 0xd8000, irq 0, can_queue 16, cmd_per_lun 2, sg_tablesize 128, this_id 7, flags { NO_DMA_FIXUP }, options { AUTOPROBE_IRQ PSEUDO_DMA } > [ 156.020369] scsi host2: scsi_scan_host_selected: <4294967295:4294967295:18446744073709551615> > [ 156.020777] scsi 2:0:0:0: scsi scan: INQUIRY pass 1 length 36 > [ 156.022046] scsi host2: main: dequeued de045600 > [ 156.022109] STATUS_REG: 00 > BASR: 00 > ICR: 00 > MODE: 00 > [ 156.022451] scsi host2: starting arbitration, id = 7 > [ 156.022740] scsi host2: won arbitration > [ 156.022806] scsi host2: selecting target 0 > [ 171.097450] scsi host2: target did not respond within 250ms > [ 171.097508] scsi host2: main: select complete > [ 171.099554] scsi 2:0:0:0: scsi scan: INQUIRY failed with code 0x40000 This is very helpful, thanks. The problem has to be this: err = NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, SR_BSY, msecs_to_jiffies(250)); which would suggest a problem with the busy wait loop. It seems that 5380 register accesses are much more expensive on PC than the platforms I've tested. > [ 171.103200] scsi 2:0:1:0: scsi scan: INQUIRY pass 1 length 36 > [ 171.105246] scsi host2: main: dequeued df6b9f00 > [ 171.105350] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 171.105664] scsi host2: starting arbitration, id = 7 > [ 171.105752] scsi host2: won arbitration > [ 171.105822] scsi host2: selecting target 1 > [ 171.105977] scsi host2: target 1 selected, going into MESSAGE OUT phase. > [ 171.106042] scsi host2: nexus established. > [ 171.106093] scsi host2: main: select complete > [ 171.106145] scsi host2: main: performing information transfer > [ 171.108531] scsi 2:0:1:0: scsi scan: INQUIRY successful with code 0x0 > [ 171.108639] scsi 2:0:1:0: scsi scan: INQUIRY pass 2 length 130 > [ 171.109401] scsi host2: main: dequeued df6b9f00 > [ 171.109485] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 171.109779] scsi host2: starting arbitration, id = 7 > [ 171.109878] scsi host2: won arbitration > [ 171.109954] scsi host2: selecting target 1 > [ 171.110112] scsi host2: target 1 selected, going into MESSAGE OUT phase. > [ 171.110181] scsi host2: nexus established. > [ 171.110236] scsi host2: main: select complete > [ 171.110286] scsi host2: main: performing information transfer > [ 171.114811] scsi 2:0:1:0: scsi scan: INQUIRY successful with code 0x0 > [ 171.114928] scsi 2:0:1:0: Direct-Access QUANTUM LP240S GM240S01X 4.6 PQ: 0 ANSI: 2 CCS > [ 171.115011] scsi target2:0:1: scsi scan: Sequential scan > [ 171.115856] scsi 2:0:1:1: scsi scan: INQUIRY pass 1 length 36 > [ 171.116008] scsi host2: main: dequeued df6b9800 > [ 171.116039] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 171.116736] scsi host2: starting arbitration, id = 7 > [ 171.116843] scsi host2: won arbitration > [ 171.116898] scsi host2: selecting target 1 > [ 171.117117] scsi host2: target 1 selected, going into MESSAGE OUT phase. > [ 171.117182] scsi host2: nexus established. > [ 171.117234] scsi host2: main: select complete > [ 171.117287] scsi host2: main: performing information transfer > [ 171.119674] scsi 2:0:1:1: scsi scan: INQUIRY successful with code 0x0 > [ 171.119781] scsi 2:0:1:1: scsi scan: INQUIRY pass 2 length 130 > [ 171.119898] scsi host2: main: dequeued df6b9800 > [ 171.119962] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 171.121426] scsi host2: starting arbitration, id = 7 > [ 171.121537] scsi host2: won arbitration > [ 171.121592] scsi host2: selecting target 1 > [ 171.121766] scsi host2: target 1 selected, going into MESSAGE OUT phase. > [ 171.121834] scsi host2: nexus established. > [ 171.121889] scsi host2: main: select complete > [ 171.121940] scsi host2: main: performing information transfer > [ 171.126361] scsi 2:0:1:1: scsi scan: INQUIRY successful with code 0x0 > [ 171.126470] scsi 2:0:1:1: scsi scan: peripheral qualifier of 3, device not added > [ 171.127735] scsi 2:0:2:0: scsi scan: INQUIRY pass 1 length 36 > [ 171.127920] scsi host2: main: dequeued df6b9800 > [ 171.127982] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 171.128648] scsi host2: starting arbitration, id = 7 > [ 171.128754] scsi host2: won arbitration > [ 171.128811] scsi host2: selecting target 2 > [ 186.203734] scsi host2: target did not respond within 250ms > [ 186.203794] scsi host2: main: select complete > [ 186.205355] scsi 2:0:2:0: scsi scan: INQUIRY failed with code 0x40000 > [ 186.208989] scsi 2:0:3:0: scsi scan: INQUIRY pass 1 length 36 > [ 186.209178] scsi host2: main: dequeued df6b9f00 > [ 186.209242] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 186.209570] scsi host2: starting arbitration, id = 7 > [ 186.209660] scsi host2: won arbitration > [ 186.209731] scsi host2: selecting target 3 > [ 201.284666] scsi host2: target did not respond within 250ms > [ 201.284726] scsi host2: main: select complete > [ 201.286193] scsi 2:0:3:0: scsi scan: INQUIRY failed with code 0x40000 > [ 201.287455] scsi 2:0:4:0: scsi scan: INQUIRY pass 1 length 36 > [ 201.287609] scsi host2: main: dequeued df6b9900 > [ 201.287673] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 201.287973] scsi host2: starting arbitration, id = 7 > [ 201.288766] scsi host2: won arbitration > [ 201.288855] scsi host2: selecting target 4 > [ 216.363793] scsi host2: target did not respond within 250ms > [ 216.363853] scsi host2: main: select complete > [ 216.363947] scsi 2:0:4:0: scsi scan: INQUIRY failed with code 0x40000 > [ 216.366469] scsi 2:0:5:0: scsi scan: INQUIRY pass 1 length 36 > [ 216.366633] scsi host2: main: dequeued df6b9f00 > [ 216.366696] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 216.366997] scsi host2: starting arbitration, id = 7 > [ 216.367153] scsi host2: won arbitration > [ 216.367208] scsi host2: selecting target 5 > [ 231.442079] scsi host2: target did not respond within 250ms > [ 231.442136] scsi host2: main: select complete > [ 231.442214] scsi 2:0:5:0: scsi scan: INQUIRY failed with code 0x40000 > [ 231.445050] scsi 2:0:6:0: scsi scan: INQUIRY pass 1 length 36 > [ 231.445329] scsi host2: main: dequeued df6b9c00 > [ 231.445392] STATUS_REG: 00 > BASR: 08 > ICR: 00 > MODE: 00 > [ 231.445682] scsi host2: starting arbitration, id = 7 > [ 231.445784] scsi host2: won arbitration > [ 231.445855] scsi host2: selecting target 6 > [ 246.521110] scsi host2: target did not respond within 250ms > [ 246.521171] scsi host2: main: select complete > [ 246.521253] scsi 2:0:6:0: scsi scan: INQUIRY failed with code 0x40000 > [ 246.525098] sd 2:0:1:0: Attached scsi generic sg1 type 0 > > > > [...] Which card(s) are affected? > > All of them: HP C2502 (53C400A), Canon FG2-5202 (53C400) and DTCT-436P. > OK. > > Aside from trying to figure out why the chip behaves oddly, we could also > > try to figure out whether the driver and its main loop is causing problems > > for other tasks i.e. timekeeping watchdog. Does this patch make any > > difference? > > The timekeeping warning does not appear when all 71 patches are applied. > Reverse-bisected it - the warning disappears after: > [PATCH 50/71] ncr5380: Change instance->host_lock to hostdata->lock > Makes sense. I think that this should solve the problem: Index: linux/drivers/scsi/NCR5380.c =================================================================== --- linux.orig/drivers/scsi/NCR5380.c 2015-11-27 09:21:40.000000000 +1100 +++ linux/drivers/scsi/NCR5380.c 2015-11-27 09:25:36.000000000 +1100 @@ -230,7 +230,7 @@ static int NCR5380_poll_politely2(struct unsigned long n; /* Busy-wait for up to 1 jiffy */ - n = loops_per_jiffy; + n = 1 + loops_per_jiffy / 10; do { if ((NCR5380_read(reg1) & bit1) == val1) return 0; --