Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932273Ab1DMTj5 (ORCPT ); Wed, 13 Apr 2011 15:39:57 -0400 Received: from mail-qw0-f46.google.com ([209.85.216.46]:45881 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932094Ab1DMTjz convert rfc822-to-8bit (ORCPT ); Wed, 13 Apr 2011 15:39:55 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=Ey8/ceWUWKVqu6pBRAjL3W3vSjJm1gFRem+5oObCOj9tJf+tFixhjXXOVjZtCz1y2j AJeDZaofluwrrJa1g2Y7lhyGPimFcA7YHTv7ve37cyw+vBd53OW/jtIKRY9C7oc8WfiX D1alciF3wJY/R+nYp3Pv/stzMiFqpihoTAkB4= MIME-Version: 1.0 In-Reply-To: <20110413163113.GA24015@kroah.com> References: <1302634375-2378-1-git-send-email-zajec5@gmail.com> <20110413163113.GA24015@kroah.com> Date: Wed, 13 Apr 2011 21:39:54 +0200 Message-ID: Subject: Re: [RFC][PATCH V4] axi: add AXI bus driver From: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= To: Greg KH Cc: linux-wireless@vger.kernel.org, "John W. Linville" , b43-dev@lists.infradead.org, =?UTF-8?Q?Michael_B=C3=BCsch?= , Larry Finger , George Kashperko , Arend van Spriel , linux-arm-kernel@lists.infradead.org, Russell King , Arnd Bergmann , Andy Botting , linuxdriverproject , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3858 Lines: 121 2011/4/13 Greg KH : >> diff --git a/drivers/axi/axi_pci_bridge.c b/drivers/axi/axi_pci_bridge.c >> new file mode 100644 >> index 0000000..17e882c >> --- /dev/null >> +++ b/drivers/axi/axi_pci_bridge.c >> @@ -0,0 +1,33 @@ >> +/* >> + * AXI PCI bridge module >> + * >> + * Licensed under the GNU/GPL. See COPYING for details. >> + */ >> + >> +#include "axi_private.h" >> + >> +#include >> +#include >> + >> +static DEFINE_PCI_DEVICE_TABLE(axi_pci_bridge_tbl) = { >> +     { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4331) }, >> +     { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4353) }, >> +     { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4727) }, >> +     { 0, }, >> +}; >> +MODULE_DEVICE_TABLE(pci, axi_pci_bridge_tbl); >> + >> +static struct pci_driver axi_pci_bridge_driver = { >> +     .name = "axi-pci-bridge", >> +     .id_table = axi_pci_bridge_tbl, >> +}; >> + >> +int __init axi_pci_bridge_init(void) >> +{ >> +     return axi_host_pci_register(&axi_pci_bridge_driver); >> +} >> + >> +void __exit axi_pci_bridge_exit(void) >> +{ >> +     axi_host_pci_unregister(&axi_pci_bridge_driver); >> +} > > You register a pci driver that does nothing?  That's not right, you need > to then base your axi bus off of that pci device, so it is hooked up > correctly in the /sys/devices/ tree.  Otherwise you are somewhere up in > the virtual location for your axi bus, right? Please take a look at: driver->probe = axi_host_pci_probe; driver->remove = axi_host_pci_remove; return pci_register_driver(driver); >> +bool axi_core_is_enabled(struct axi_device *core) >> +{ >> +     if ((axi_aread32(core, AXI_IOCTL) & (AXI_IOCTL_CLK | AXI_IOCTL_FGC)) >> +         != AXI_IOCTL_CLK) >> +             return false; >> +     if (axi_aread32(core, AXI_RESET_CTL) & AXI_RESET_CTL_RESET) >> +             return false; >> +     return true; >> +} >> +EXPORT_SYMBOL(axi_core_is_enabled); > > EXPORT_SYMBOL_GPL()? > > What module uses this?  And why would it care? > >> +EXPORT_SYMBOL(axi_core_enable); > > EXPORT_SYMBOL_GPL()? > > Same goes for your other exports, just want you to be sure here. Hm, I'm not sure. Using EXPORT_SYMBOL_GPL will forbid closed source drivers from using our bus driver, right? I'm don't have preferences on this, if you prefer us to force GPL, I can. >> +u32 xaxi_chipco_gpio_control(struct axi_drv_cc *cc, u32 mask, u32 value) >> +{ >> +     return axi_cc_write32_masked(cc, AXI_CC_GPIOCTL, mask, value); >> +} >> +EXPORT_SYMBOL(xaxi_chipco_gpio_control); > > "xaxi"?  Shouldn't that be consistant with the other exports and start > with "axi"? Left from old tests/rewrites/splitting. Thanks. >> +static u8 axi_host_pci_read8(struct axi_device *core, u16 offset) >> +{ >> +     if (unlikely(core->bus->mapped_core != core)) > > Are you sure about the use of unlikely in this, and other functions? > The compiler almost always does a better job than we do for these types > of calls, just let it do it's job. > >> +             axi_host_pci_switch_core(core); >> +     return ioread8(core->bus->mmio + offset); > > I think because of that unlikely, you just slowed down all pci devices, > right?  That's not very nice :) Hm, my logic suggests it is alright, but please consider this once more with me ;) For the most of the time mapped_core (active core) do not change. We perform few hundreds of operations on one core in a row. This way mapped_core points to passed core for most of the time. Condition (mapped_core != core) is unlikely to happen. Is there anything wrong in my logic? -- Rafał -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/