Date:   Thu, 09 Mar 2023 11:51:18 +0100
Message-ID: <87356egpuh.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Wesley Cheng <quic_wcheng@quicinc.com>
Cc:     <srinivas.kandagatla@linaro.org>, <mathias.nyman@intel.com>,
        <perex@perex.cz>, <broonie@kernel.org>, <lgirdwood@gmail.com>,
        <krzysztof.kozlowski+dt@linaro.org>, <agross@kernel.org>,
        <Thinh.Nguyen@synopsys.com>, <bgoswami@quicinc.com>,
        <andersson@kernel.org>, <robh+dt@kernel.org>,
        <gregkh@linuxfoundation.org>, <tiwai@suse.com>,
        <linux-kernel@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <alsa-devel@alsa-project.org>, <devicetree@vger.kernel.org>,
        <linux-usb@vger.kernel.org>, <quic_jackp@quicinc.com>,
        <quic_plai@quicinc.com>,
        Mathias Nyman <mathias.nyman@linux.intel.com>
Subject: Re: [PATCH v3 01/28] xhci: Add support to allocate several interrupters
In-Reply-To: <20230308235751.495-2-quic_wcheng@quicinc.com>
References: <20230308235751.495-1-quic_wcheng@quicinc.com>
        <20230308235751.495-2-quic_wcheng@quicinc.com>
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On Thu, 09 Mar 2023 00:57:24 +0100,
Wesley Cheng wrote:
> +struct xhci_interrupter *
> +xhci_create_secondary_interrupter(struct usb_hcd *hcd, int intr_num)
> +{
> +	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> +	struct xhci_interrupter *ir;
> +	unsigned int i;
> +	unsigned int idx = 0;
> +	unsigned long flags;
> +
> +	if (!xhci->interrupters || intr_num > xhci->max_interrupters)
> +		return NULL;
> +
> +	spin_lock_irqsave(&xhci->lock, flags);
....
> +	if (idx > 0) {
> +		ir = xhci_alloc_interrupter(xhci, idx, GFP_KERNEL);
> +		if (!ir) {
> +			spin_unlock_irqrestore(&xhci->lock, flags);
> +			return NULL;
> +		}
> +		ir->intr_num = idx;
> +		xhci->interrupters[idx] = ir;
> +		spin_unlock_irqrestore(&xhci->lock, flags);

You can't use GFP_KERNEL allocation inside the spinlock.


Takashi