From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arthur Marsh Subject: Re: eata - issue appeared in Linus git master in last 24-48 hours Date: Sat, 12 Jul 2014 14:43:39 +0930 Message-ID: <53C0C403.1010503@internode.on.net> References: <20140711092006.GB26912@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:46940 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751089AbaGLFNp (ORCPT ); Sat, 12 Jul 2014 01:13:45 -0400 In-Reply-To: <20140711092006.GB26912@infradead.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: linux-scsi@vger.kernel.org Christoph Hellwig wrote, on 11/07/14 18:50: > On Mon, Jun 30, 2014 at 04:31:33AM +0930, Arthur Marsh wrote: >> Hi, I haven't had time to do a git bisect yet, but just saw this after >> rebuilding the kernel in the last day or so: > > It seems like some of the routines called during the driver > initialization may sleep while the driver_lock is held and irqs are > disabled. > > As eata2x_detect is only called during module load the lock seems > entirely pointless and should be removed, like in the patch below: > > > diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c > index 03372cf..980898e 100644 > --- a/drivers/scsi/eata.c > +++ b/drivers/scsi/eata.c > @@ -837,7 +837,6 @@ struct hostdata { > static struct Scsi_Host *sh[MAX_BOARDS]; > static const char *driver_name = "EATA"; > static char sha[MAX_BOARDS]; > -static DEFINE_SPINLOCK(driver_lock); > > /* Initialize num_boards so that ihdlr can work while detect is in progress */ > static unsigned int num_boards = MAX_BOARDS; > @@ -1097,8 +1096,6 @@ static int port_detect(unsigned long port_base, unsigned int j, > goto fail; > } > > - spin_lock_irq(&driver_lock); > - > if (do_dma(port_base, 0, READ_CONFIG_PIO)) { > #if defined(DEBUG_DETECT) > printk("%s: detect, do_dma failed at 0x%03lx.\n", name, > @@ -1265,10 +1262,7 @@ static int port_detect(unsigned long port_base, unsigned int j, > } > #endif > > - spin_unlock_irq(&driver_lock); > sh[j] = shost = scsi_register(tpnt, sizeof(struct hostdata)); > - spin_lock_irq(&driver_lock); > - > if (shost == NULL) { > printk("%s: unable to register host, detaching.\n", name); > goto freedma; > @@ -1345,8 +1339,6 @@ static int port_detect(unsigned long port_base, unsigned int j, > else > sprintf(dma_name, "DMA %u", dma_channel); > > - spin_unlock_irq(&driver_lock); > - > for (i = 0; i < shost->can_queue; i++) > ha->cp[i].cp_dma_addr = pci_map_single(ha->pdev, > &ha->cp[i], > @@ -1439,7 +1431,6 @@ static int port_detect(unsigned long port_base, unsigned int j, > freeirq: > free_irq(irq, &sha[j]); > freelock: > - spin_unlock_irq(&driver_lock); > release_region(port_base, REGION_SIZE); > fail: > return 0; > Thanks, I've rebuilt the kernel with this patch applied and running the rebuilt kernel fine using a DPT 2044W SCSI adaptor: $ lspci|grep DPT 00:0c.0 SCSI storage controller: Adaptec (formerly DPT) SmartCache/Raid I-IV Controller (rev 02) $ dmesg|grep -i eata [ 1.038968] EATA0: warning, DMA protocol support not asserted. [ 1.039041] EATA0: IRQ 11 mapped to IO-APIC IRQ 16. [ 1.040801] EATA/DMA 2.0x: Copyright (C) 1994-2003 Dario Ballabio. [ 1.040861] EATA config options -> tm:1, lc:y, mq:16, rs:y, et:n, ip:n, ep:n, pp:y. [ 1.040922] EATA0: 2.0C, PCI 0x7410, IRQ 16, BMST, SG 122, MB 64. [ 1.040973] EATA0: wide SCSI support enabled, max_id 16, max_lun 8. [ 1.041025] EATA0: SCSI channel 0 enabled, host target ID 7. [ 1.041095] scsi2 : EATA/DMA 2.0x rev. 8.10.00 Arthur.