From: Robin Gong <yibin.gong@nxp.com>
To: Lucas Stach <l.stach@pengutronix.de>,
"vkoul@kernel.org" <vkoul@kernel.org>,
"s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"jslaby@suse.com" <jslaby@suse.com>
Cc: "linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
"dmaengine@vger.kernel.org" <dmaengine@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
dl-linux-imx <linux-imx@nxp.com>
Subject: RE: [PATCH v5 0/7] add virt-dma support for imx-sdma
Date: Wed, 27 Jun 2018 01:18:05 +0000 [thread overview]
Message-ID: <DB6PR04MB3223F2B6364A63A00A251DF689480@DB6PR04MB3223.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <1530025442.9910.44.camel@pengutronix.de>
Thanks Lucas. Let's wait for comments from Vinod.
-----Original Message-----
From: Lucas Stach [mailto:l.stach@pengutronix.de]
Sent: 2018年6月26日 23:04
To: Robin Gong <yibin.gong@nxp.com>; vkoul@kernel.org; s.hauer@pengutronix.de; dan.j.williams@intel.com; gregkh@linuxfoundation.org; jslaby@suse.com
Cc: linux-serial@vger.kernel.org; dmaengine@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org; dl-linux-imx <linux-imx@nxp.com>
Subject: Re: [PATCH v5 0/7] add virt-dma support for imx-sdma
Hi Robin,
I've tested this whole series with the SDMA being used for SPI, UART and SSI with no regressions spotted. As this should cover most common use-cases, I think this series is good to go in.
Tested-by: Lucas Stach <l.stach@pengutronix.de>
Regards,
Lucas
Am Mittwoch, den 20.06.2018, 00:56 +0800 schrieb Robin Gong:
> The legacy sdma driver has below limitations or drawbacks:
> 1. Hardcode the max BDs number as "PAGE_SIZE / sizeof(*)", and alloc
> one page size for one channel regardless of only few BDs needed
> most time. But in few cases, the max PAGE_SIZE maybe not enough.
> 2. One SDMA channel can't stop immediatley once channel disabled
> which
> means SDMA interrupt may come in after this channel
> terminated.There
> are some patches for this corner case such as commit
> "2746e2c389f9",
> but not cover non-cyclic.
>
> The common virt-dma overcomes the above limitations. It can alloc bd
> dynamically and free bd once this tx transfer done. No memory wasted
> or maximum limititation here, only depends on how many memory can be
> requested from kernel. For No.2, such issue can be workaround by
> checking if there is available descript("sdmac->desc") now once the
> unwanted interrupt coming. At last the common virt-dma is easier for sdma driver maintain.
>
> Change from v4:
> 1. identify lockdep issue which caused by allocate memory with
> 'GFP_KERNEL', change to 'GFP_NOWAIT' instead so that lockdep
> ignore check. That also make sense since Audio/uart driver may
> call dma function after spin_lock_irqsave()...
> 2. use dma pool instead for bd description allocated,since audio
> driver may call dma_terminate_all in irq. Please refer to 7/7.
> 3. remove 7/7 serial patch in v4, since lockdep issued fixed by No.1
>
> Change from v3:
> 1. add two uart patches which impacted by this patchset.
> 2. unlock 'vc.lock' before cyclic dma callback and lock again after
> it because some driver such as uart will call dmaengine_tx_status
> which will acquire 'vc.lock' again and dead lock comes out.
> 3. remove 'Revert commit' stuff since that patch is not wrong and
> combine two patch into one patch as Sascha's comment.
>
> Change from v2:
> 1. include Sascha's patch to make the main patch easier to review.
> Thanks Sacha.
> 2. remove useless 'desc'/'chan' in struct sdma_channe.
>
> Change from v1:
> 1. split v1 patch into 5 patches.
> 2. remove some unnecessary condition check.
> 3. remove unnecessary 'pending' list.
>
> Robin Gong (6):
> tty: serial: imx: correct dma cookie status
> dmaengine: imx-sdma: add virt-dma support
> dmaengine: imx-sdma: remove useless 'lock' and 'enabled' in 'struct
> sdma_channel'
> dmaengine: imx-sdma: remove the maximum limitation for bd numbers
> dmaengine: imx-sdma: add sdma_transfer_init to decrease code overlap
> dmaengine: imx-sdma: alloclate bd memory from dma pool
>
> Sascha Hauer (1):
> dmaengine: imx-sdma: factor out a struct sdma_desc from struct
> sdma_channel
>
> drivers/dma/Kconfig | 1 +
> drivers/dma/imx-sdma.c | 400
> +++++++++++++++++++++++++++--------------------
> drivers/tty/serial/imx.c | 2 +-
> 3 files changed, 235 insertions(+), 168 deletions(-)
>
next prev parent reply other threads:[~2018-06-27 1:18 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-19 16:56 [PATCH v5 0/7] add virt-dma support for imx-sdma Robin Gong
2018-06-19 16:56 ` [PATCH v5 1/7] tty: serial: imx: correct dma cookie status Robin Gong
2018-06-26 19:22 ` Uwe Kleine-König
2018-06-29 11:03 ` Vinod
2018-06-19 16:56 ` [PATCH v5 2/7] dmaengine: imx-sdma: factor out a struct sdma_desc from struct sdma_channel Robin Gong
2018-06-19 16:57 ` [PATCH v5 3/7] dmaengine: imx-sdma: add virt-dma support Robin Gong
2018-06-19 16:57 ` [PATCH v5 4/7] dmaengine: imx-sdma: remove useless 'lock' and 'enabled' in 'struct sdma_channel' Robin Gong
2018-06-19 16:57 ` [PATCH v5 5/7] dmaengine: imx-sdma: remove the maximum limitation for bd numbers Robin Gong
2018-06-19 16:57 ` [PATCH v5 6/7] dmaengine: imx-sdma: add sdma_transfer_init to decrease code overlap Robin Gong
2018-06-19 16:57 ` [PATCH v5 7/7] dmaengine: imx-sdma: alloclate bd memory from dma pool Robin Gong
2018-08-06 12:44 ` Lucas Stach
2018-06-22 1:12 ` [PATCH v5 0/7] add virt-dma support for imx-sdma Robin Gong
2018-06-22 6:14 ` Sascha Hauer
2018-06-26 15:04 ` Lucas Stach
2018-06-27 1:18 ` Robin Gong [this message]
2018-07-02 2:32 ` Robin Gong
2018-07-02 13:17 ` Vinod
2018-07-03 2:57 ` Robin Gong
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=DB6PR04MB3223F2B6364A63A00A251DF689480@DB6PR04MB3223.eurprd04.prod.outlook.com \
--to=yibin.gong@nxp.com \
--cc=dan.j.williams@intel.com \
--cc=dmaengine@vger.kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=jslaby@suse.com \
--cc=l.stach@pengutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=s.hauer@pengutronix.de \
--cc=vkoul@kernel.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;
as well as URLs for NNTP newsgroup(s).