mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Yann Sionneau <ysionneau@kalray.eu>
To: Andrey Smirnov <andrew.smirnov@gmail.com>, barebox@lists.infradead.org
Subject: Re: [PATCH 02/25] usb: xhci-hcd: Do not zero out DMA coherent memory
Date: Wed, 20 Feb 2019 10:29:49 +0100	[thread overview]
Message-ID: <f18cf7da-6ca0-d3b6-0a77-9da7bef39276@kalray.eu> (raw)
In-Reply-To: <20190220072930.14300-3-andrew.smirnov@gmail.com>

I'm not sure dma_alloc_coherent() should return zeroed out memory.

I'm pretty sure it does not.

mips arch seems to memset it to 0, but not all arch do that.

On 2/20/19 8:29 AM, Andrey Smirnov wrote:
> Memory returned by dma_alloc_coherent() should already be zeroed
> out, so there's no need to do this explicitly.
>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>   drivers/usb/host/xhci-hcd.c | 2 --
>   1 file changed, 2 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-hcd.c b/drivers/usb/host/xhci-hcd.c
> index 7cfd74de4..7106a5637 100644
> --- a/drivers/usb/host/xhci-hcd.c
> +++ b/drivers/usb/host/xhci-hcd.c
> @@ -445,7 +445,6 @@ static struct xhci_virtual_device *xhci_alloc_virtdev(struct xhci_hcd *xhci,
>   
>   	vdev->dma_size = sz_ictx + sz_dctx;
>   	p = vdev->dma = dma_alloc_coherent(vdev->dma_size, DMA_ADDRESS_BROKEN);
> -	memset(vdev->dma, 0, vdev->dma_size);
>   
>   	vdev->out_ctx = p; p += sz_dctx;
>   	vdev->in_ctx = p; p += sz_ictx;
> @@ -1225,7 +1224,6 @@ static void xhci_dma_alloc(struct xhci_hcd *xhci)
>   	xhci->dma_size += num_ep * sz_ep;
>   
>   	p = xhci->dma = dma_alloc_coherent(xhci->dma_size, DMA_ADDRESS_BROKEN);
> -	memset(xhci->dma, 0, xhci->dma_size);
>   
>   	xhci->sp = p; p += sz_sp;
>   	xhci->dcbaa = p; p += sz_dca;

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

  reply	other threads:[~2019-02-20  9:29 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-20  7:29 [PATCH 00/25] i.MX8MQ USB support Andrey Smirnov
2019-02-20  7:29 ` [PATCH 01/25] usb: xhci-hcd: Tabify the file Andrey Smirnov
2019-02-20  7:29 ` [PATCH 02/25] usb: xhci-hcd: Do not zero out DMA coherent memory Andrey Smirnov
2019-02-20  9:29   ` Yann Sionneau [this message]
2019-02-20 18:54     ` Andrey Smirnov
2019-02-23 10:16     ` Sam Ravnborg
2019-02-20  7:29 ` [PATCH 03/25] usb: xhci-hcd: Cast ~XHCI_IRQS to u32 Andrey Smirnov
2019-02-20  7:29 ` [PATCH 04/25] usb: xhci-hcd: Make sure to initialize xhci->rings_list Andrey Smirnov
2019-02-20  7:29 ` [PATCH 05/25] usb: xhci-hcd: Drop pointless bitwise or Andrey Smirnov
2019-02-20  7:29 ` [PATCH 06/25] usb: xhci-hcd: Add support for 64-byte context size Andrey Smirnov
2019-02-20  7:29 ` [PATCH 07/25] usb: xhci-hcd: Don't try to DMA sync if buffer is NULL Andrey Smirnov
2019-02-20  7:29 ` [PATCH 08/25] usb: xhci-hcd: Always wait for "Response Data" completion Andrey Smirnov
2019-02-20  7:29 ` [PATCH 09/25] usb: xhci-hcd: Convert xhci_submit_normal() to use dma_map_single() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 10/25] usb: xhci-hcd: Convert xhci_submit_control() " Andrey Smirnov
2019-02-20  7:29 ` [PATCH 11/25] usb: xhci-hcd: Simplify TRB initialization code Andrey Smirnov
2019-02-20  7:29 ` [PATCH 12/25] usb: xhci-hcd: Drop 'dma' field from struct xhci_hcd Andrey Smirnov
2019-02-20  7:29 ` [PATCH 13/25] usb: xhci-hcd: Check usb_pipein(pipe) only once in xhci_submit_normal() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 14/25] usb: xhci-hcd: Initialize TRT flag for xHCI >= 1.0 Andrey Smirnov
2019-02-20  7:29 ` [PATCH 15/25] usb: xhci-hcd: Simplify route string building loop Andrey Smirnov
2019-02-20  7:29 ` [PATCH 16/25] usb: xhci-hcd: Make use of lo_hi_readq/writeq() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 17/25] phy: core: Assume EPROBE_DEFER in of_phy_provider_lookup() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 18/25] phy: Port i.MX8MQ USB PHY driver from Linux Andrey Smirnov
2019-02-20  7:29 ` [PATCH 19/25] clk: Drop separate definitions of clk_put() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 20/25] include/usb: Import USB_SPEED_SUPER_PLUS from Linux Andrey Smirnov
2019-02-20  7:29 ` [PATCH 21/25] clk: Import a subset of clk_bulk API " Andrey Smirnov
2019-02-20  7:29 ` [PATCH 22/25] usb: Import DWC3 USB controller driver " Andrey Smirnov
2019-02-20  7:29 ` [PATCH 23/25] lib: Port basic Linux kernel NLS functions Andrey Smirnov
2019-02-20  7:29 ` [PATCH 24/25] usb: Port Microchip USB251x USB hub driver from Linux Andrey Smirnov
2019-02-20  7:29 ` [PATCH 25/25] usb: usb251xb: add usb data lane port swap feature Andrey Smirnov
2019-02-22  7:27 ` [PATCH 00/25] i.MX8MQ USB support Sascha Hauer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f18cf7da-6ca0-d3b6-0a77-9da7bef39276@kalray.eu \
    --to=ysionneau@kalray.eu \
    --cc=andrew.smirnov@gmail.com \
    --cc=barebox@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox