From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com ([134.134.136.24]:49082 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751852AbbINId1 (ORCPT ); Mon, 14 Sep 2015 04:33:27 -0400 Subject: Re: [Bugfix 3/3] eata: Enhance eata driver to support PCI device hot-removal To: "Ballabio, Dario" , Hannes Reinecke , Thomas Gleixner , Bjorn Helgaas , Arthur Marsh , "James E.J. Bottomley" References: <1442200140-30808-1-git-send-email-jiang.liu@linux.intel.com> <1442200140-30808-4-git-send-email-jiang.liu@linux.intel.com> <55F6837A.5020807@suse.de> Cc: "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "x86@kernel.org" From: Jiang Liu Message-ID: <55F68654.4070709@linux.intel.com> Date: Mon, 14 Sep 2015 16:33:24 +0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Sender: linux-pci-owner@vger.kernel.org List-ID: On 2015/9/14 16:31, Ballabio, Dario wrote: > Agreed, It does not make sense to have this driver converted to a hot plug api. Thanks, got the point:) Originally i thought user may trigger PCI device hot-removal by sysfs interfaces and there's comment mentioning that eata driver breaks PCI hotplug, so I tried to solve it. If it's no real use, we may just drop the third patch. Thanks! Gerry > > Cheers, > > > > *************************************** > Ph.D. Dario Ballabio > Principal Field Support Specialist, EMC EMEA > Mobile phone: +393487978851 > > > > -----Original Message----- > From: Hannes Reinecke [mailto:hare@suse.de] > Sent: Monday, September 14, 2015 10:21 AM > To: Jiang Liu; Thomas Gleixner; Bjorn Helgaas; Arthur Marsh; Ballabio, Dario; James E.J. Bottomley > Cc: linux-kernel@vger.kernel.org; linux-pci@vger.kernel.org; linux-scsi@vger.kernel.org; x86@kernel.org > Subject: Re: [Bugfix 3/3] eata: Enhance eata driver to support PCI device hot-removal > > On 09/14/2015 05:08 AM, Jiang Liu wrote: >> Due to having no hardware for testing, this is just a sample code to >> support PCI device hot-removal. It just passing compilation, no any >> tests. >> >> Signed-off-by: Jiang Liu >> --- >> drivers/scsi/eata.c | 26 ++++++++++++++++++++++++++ >> 1 file changed, 26 insertions(+) >> >> diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c index >> b92e6856f909..f3bd7cbf260e 100644 >> --- a/drivers/scsi/eata.c >> +++ b/drivers/scsi/eata.c >> @@ -1474,6 +1474,21 @@ static unsigned int port_probe(unsigned long >> port_base, #ifdef CONFIG_PCI static int eata2x_pci_device_count; >> >> +/* TODO: need help here to shutdown the scsi host and release >> +resources */ static void port_remove(unsigned int id, resource_size_t port_base, >> + struct pci_dev *pdev) >> +{ >> + struct Scsi_Host *shost = sh[id]; >> + >> + /* TODO: stop scsi device */ >> + scsi_unregister(shost); >> + /* TODO: clean up resources allocated by port_detect() */ >> + clear_bit(id, eata_board_bitmap); >> + free_irq(shost->irq, &sha[id]); >> + release_region(port_base, REGION_SIZE); >> + ida_simple_remove(&eata_ida, id); >> +} >> + >> static int eata2x_pci_probe(struct pci_dev *dev, const struct >> pci_device_id *id) { >> int i, ret = -ENXIO; >> @@ -1521,6 +1536,16 @@ out_error: >> return ret; >> } >> >> +static void eata2x_pci_remove(struct pci_dev *pdev) { >> + int id = (int)(long)dev_get_drvdata(&pdev->dev); >> + resource_size_t port_base; >> + >> + port_base = pci_resource_start(pdev, 0) + PCI_BASE_ADDRESS_0; >> + port_remove(id, port_base, pdev); >> + pci_disable_device(pdev); >> +} >> + >> static struct pci_device_id eata2x_tbl[] = { >> { PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_SCSI << 8, PCI_ANY_ID) }, >> { }, >> @@ -1531,6 +1556,7 @@ static struct pci_driver eata2x_pci_driver = { >> .name = "eata", >> .id_table = eata2x_tbl, >> .probe = eata2x_pci_probe, >> + .remove = eata2x_pci_remove, >> }; >> >> static int eata2x_probe_pci_devices(struct scsi_host_template *tpnt) >> > Welll ... if you don't have hardware (and I strongly hope you refer to 'hardware able to do hotplugging', not 'hardware for the eata driver' > ...) why add the code at all? > Chances are no-one will ever need eata PCI hotplug; SCSI parallel typically isn't very good at hotplugging, so throwing in PCI hotplug will only confuse matters more. > Plus due to the sheer mechanics involved here I find it very unlikely anyone will be using it in real life. > > Cheers, > > Hannes >