From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B9A122DFBC for ; Wed, 15 Jan 2025 02:30:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736908203; cv=none; b=U60/LL6/Diiw/1PR2xVGd8EgqLfpqLAv0gYZ67Ko2IUO6lnE64LmLLYIcn8o1+lxvQstCfr/Ba6svn/iD8PBOt9aTlzv9TFfekuHnTneLq4JcuswusklYGBD6crm1FgeOEnGldF5pC+IwwTBUymJ/DwXWKus2tHmJib3F9Cahos= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736908203; c=relaxed/simple; bh=hDtidHG2klDA+GHJV7uxRQsGYJylJGa+fqYRLBGwfs0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Mg5XQzsAtjBVhMZpzWlGP/OJoVs9inr3NfEM0rBG0juwZrM3UaJ432/1DYEQxFBGCW4q9SJDsg1zS0wVGET3+4QX2PkNOc7KI+rES1Z7QTEX02fShN8R3Y+4aBXJxs+UlOjhPOCaQPn/sJ19DZVO92ec3icIIknGc7IZZaULBQ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EJrtRQ5m; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EJrtRQ5m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D3D9C4CEDD; Wed, 15 Jan 2025 02:30:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736908202; bh=hDtidHG2klDA+GHJV7uxRQsGYJylJGa+fqYRLBGwfs0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=EJrtRQ5m4vIfpXHxxMOmDeyn6XVM7jsSNH7YVWzzotkxT9T02UIZJr2Lfs/xUzK5z CLqYWC2ZXtLkDSB60MXof86/xrMu5Khr9Emrk/hmDtBc+IiLAayXj1r6EGDFltIlkc M2bfZHbdzieFmU3NfLyKO5bO/s0mC5dNVJkgf31Vox1Pg2Lji5/qodCFBHusBITnS5 FanmkOIiWh1Ie7CM9+rCjuJM2/F8sLQ/IJoEP1S5qdFGxBtw7oFK++2K0jXHdDpTIL vJA0fm0VffZfl4YTDldigjmN/Q4UHWDzD5OmUbML4ulQmXLVMHe7Wmslg95Dew+FJo P0hK0D5Y9kymQ== Message-ID: <0e2a0f69-7b98-4b48-8a68-6a554cbbec09@kernel.org> Date: Wed, 15 Jan 2025 11:30:01 +0900 Precedence: bulk X-Mailing-List: linux-ide@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V3] ata: ahci: simplify init function To: Tomas Henzl , linux-ide@vger.kernel.org Cc: Niklas.Cassel@wdc.com References: <20250114182956.40923-1-thenzl@redhat.com> From: Damien Le Moal Content-Language: en-US Organization: Western Digital Research In-Reply-To: <20250114182956.40923-1-thenzl@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 1/15/25 03:29, Tomas Henzl wrote: > by removing few lines. No functional change. > > The main part of this change is done by adding a PCI_IRQ_INTX flag into > an already existing pci_alloc_irq_vectors invocation. > In the current implementation of the pci_alloc_irq_vectors is the sequence of calls > msi-x -> msi -> legacy irq and whatever there succeeds stops the > call chain. That makes it impossible to merge all instances into as a single call > to pci_alloc_irq_vectors since the order of calls there is: > multiple msi-x > a single msi > a single msi-x > a legacy irq. > but the two last steps can be merged into one which are the msi-x and legacy > irq option. With this change we remove a pci(m)_intx call. > When PCI_IRQ_INTX flag is set the pci_alloc_irq_vectors succeeds in almost > all cases - that makes it possible to convert ahci_init_irq(msi) into a void function. > The exception is when dev->irq is zero then the pci_alloc_irq_vectors > may return with an error code also pci_intx isn't called from pci_alloc_irq_vectors > and thus certain pci calls aren't performed. > That's just a negligible issue as later in ahci_init_one the (zero) > value of dev->irq is via pci_irq_vector assigned to hpriv->irq. > That value is then later tested in ahci_host_activate->ata_host_activate where > it is welcomed with a WARN_ON message and fails with setting up irq and > then the probe function (ahci_init_one) fails. The special zero value's > meaning is that polling mode is being be set up which isn't the case. > Extra blank line not need here. Beside that, looks OK now. But as Niklas pointed out, this conflicts with a patch in the PCI tree. And given that it is too late to queue that for 6.14, can you resend a rebased version once 6.14-rc1 is out in a couple of weeks ? Thanks ! > > Signed-off-by: Tomas Henzl > --- > V2: ahci_init_irq is now a void function > V3: a) added an explanation of why we may convert ahci_init_irq into > a void function > b) fixed the subject line > c) added an explanation of why calling pci_alloc_irq_vectors instead > of pci_intx is safe > d) rebased to latest code state (pci_intx->pcim_intx) > > drivers/ata/ahci.c | 23 ++++++++++++----------- > 1 file changed, 12 insertions(+), 11 deletions(-) > > diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c > index 8d27c567be1c..3ea2f3adf354 100644 > --- a/drivers/ata/ahci.c > +++ b/drivers/ata/ahci.c > @@ -1665,13 +1665,15 @@ static int ahci_get_irq_vector(struct ata_host *host, int port) > return pci_irq_vector(to_pci_dev(host->dev), port); > } > > -static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports, > +static void ahci_init_irq(struct pci_dev *pdev, unsigned int n_ports, > struct ahci_host_priv *hpriv) > { > int nvec; > > - if (hpriv->flags & AHCI_HFLAG_NO_MSI) > - return -ENODEV; > + if (hpriv->flags & AHCI_HFLAG_NO_MSI) { > + pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX); > + return; > + } > > /* > * If number of MSIs is less than number of ports then Sharing Last > @@ -1685,7 +1687,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports, > if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) { > hpriv->get_irq_vector = ahci_get_irq_vector; > hpriv->flags |= AHCI_HFLAG_MULTI_MSI; > - return nvec; > + return; > } > > /* > @@ -1700,12 +1702,13 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports, > > /* > * If the host is not capable of supporting per-port vectors, fall > - * back to single MSI before finally attempting single MSI-X. > + * back to single MSI before finally attempting single MSI-X or > + * a legacy INTx. > */ > nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI); > if (nvec == 1) > - return nvec; > - return pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX); > + return; > + pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_INTX); > } > > static void ahci_mark_external_port(struct ata_port *ap) > @@ -1985,10 +1988,8 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) > } > host->private_data = hpriv; > > - if (ahci_init_msi(pdev, n_ports, hpriv) < 0) { > - /* legacy intx interrupts */ > - pcim_intx(pdev, 1); > - } > + ahci_init_irq(pdev, n_ports, hpriv); > + > hpriv->irq = pci_irq_vector(pdev, 0); > > if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss) -- Damien Le Moal Western Digital Research