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From: Christoph Hellwig <hch@infradead.org>
To: Sanket Parmar <sparmar@cadence.com>
Cc: peter.chen@kernel.org, pawell@cadence.com, a-govindraju@ti.com,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	kurahul@cadence.com, gregkh@linuxfoundation.org, kishon@ti.com
Subject: Re: [PATCH 2/2] usb: cdns3: Optimize DMA request buffer allocation
Date: Tue, 9 Mar 2021 09:28:04 +0000	[thread overview]
Message-ID: <20210309092804.GA76839@infradead.org> (raw)
In-Reply-To: <1615267180-9289-2-git-send-email-sparmar@cadence.com>

On Tue, Mar 09, 2021 at 06:19:40AM +0100, Sanket Parmar wrote:
> dma_alloc_coherent() might fail on the platform with a small DMA region.
> 
> To avoid such failure in cdns3_prepare_aligned_request_buf(),
> dma_alloc_coherent() is replaced with kmalloc and dma_map API to
> allocate aligned request buffer of dynamic length.

dma_alloc_noncoherent is the proper API instead of using kmalloc, which
can lead to unaddressable memory that might require bounce buffering.

  reply	other threads:[~2021-03-09  9:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-09  5:19 [PATCH 1/2] usb: cdns3: Use dma_pool_* api to alloc trb pool Sanket Parmar
2021-03-09  5:19 ` [PATCH 2/2] usb: cdns3: Optimize DMA request buffer allocation Sanket Parmar
2021-03-09  9:28   ` Christoph Hellwig [this message]
2021-03-09 10:18     ` Sanket Parmar
2021-03-09 10:31       ` Christoph Hellwig
2021-03-09 10:49         ` Sanket Parmar
2021-03-14  5:10   ` Peter Chen
2021-03-15 15:51     ` Sanket Parmar
2021-03-16  0:33       ` Peter Chen
2021-03-14  2:49 ` [PATCH 1/2] usb: cdns3: Use dma_pool_* api to alloc trb pool Peter Chen
2021-03-15  6:11   ` Sanket Parmar

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