From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [v3,3/3] dmaengine: imx-sdma: allocate max 20 bds for one transfer From: Lucas Stach Message-Id: <1532343252.3163.99.camel@pengutronix.de> Date: Mon, 23 Jul 2018 12:54:12 +0200 To: Robin Gong , vkoul@kernel.org, dan.j.williams@intel.com, s.hauer@pengutronix.de, linux@armlinux.org.uk Cc: dmaengine@vger.kernel.org, linux-imx@nxp.com, kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-ID: QW0gRGllbnN0YWcsIGRlbiAyNC4wNy4yMDE4LCAwMTo0NiArMDgwMCBzY2hyaWViIFJvYmluIEdv bmc6Cj4gSWYgbXVsdGktYmRzIHVzZWQgaW4gb25lIHRyYW5zZmVyLCBhbGwgYmRzIHNob3VsZCBi ZSBjb25zaXN0ZW4KPiBtZW1vcnkuVG8gZWFzaWx5IGZvbGxvdyBpdCwgZW5sYXJnZSB0aGUgZG1h IHBvb2wgc2l6ZSBpbnRvIDIwIGJkcywKPiBhbmQgaXQgd2lsbCByZXBvcnQgZXJyb3IgaWYgdGhl IG51bWJlciBvZiBiZHMgaXMgb3ZlciB0aGFuIDIwLiBGb3IKPiBkbWF0ZXN0LCB0aGUgbWF4IGNv dW50IGZvciBzaW5nbGUgdHJhbnNmZXIgaXMgTlVNX0JEICoKPiBTRE1BX0JEX01BWF9DTlQgPSAy MCAqIDY1NTM1ID0gfjEuMjhNQi4KCkJvdGggdGhlIGNvbW1pdCBtZXNzYWdlIGFuZCB0aGUgY29t bWVudCBuZWVkIGEgbG90IG1vcmUgY2FyZSB0bwphY3R1YWxseSB0ZWxsIHdoYXQgdGhpcyBjb21t aXQgaXMgdHJ5aW5nIHRvIGFjaGlldmUuIEN1cnJlbnRseSBJIGRvbid0CmZvbGxvdyBhdCBhbGwu IFdoYXQgZG9lcyAiY29uc2lzdGVuIiBtZWFuPyBEbyB5b3UgbWVhbiBCRHMgc2hvdWxkIGJlCmNv bnRpZ3VvdXMgaW4gbWVtb3J5PwoKV2hhdCBkbyB5b3UgZ2FpbiBieSBvdmVyLWFsbG9jYXRpbmcg ZWFjaCBCRCBieSBhIGZhY3RvciBvZiAyMD8KClJlZ2FyZHMsCkx1Y2FzCgo+IFNpZ25lZC1vZmYt Ynk6IFJvYmluIEdvbmcgPHlpYmluLmdvbmdAbnhwLmNvbT4KPiAtLS0KPiDCoGRyaXZlcnMvZG1h L2lteC1zZG1hLmMgfCAxNyArKysrKysrKysrKysrKysrLQo+IMKgMSBmaWxlIGNoYW5nZWQsIDE2 IGluc2VydGlvbnMoKyksIDEgZGVsZXRpb24oLSkKPiAKPiBkaWZmIC0tZ2l0IGEvZHJpdmVycy9k bWEvaW14LXNkbWEuYyBiL2RyaXZlcnMvZG1hL2lteC1zZG1hLmMKPiBpbmRleCBiNGVjMmQyLi41 OTczNDg5IDEwMDY0NAo+IC0tLSBhL2RyaXZlcnMvZG1hL2lteC1zZG1hLmMKPiArKysgYi9kcml2 ZXJzL2RtYS9pbXgtc2RtYS5jCj4gQEAgLTI5OCw2ICsyOTgsMTUgQEAgc3RydWN0IHNkbWFfY29u dGV4dF9kYXRhIHsKPiA+IMKgCXUzMsKgwqBzY3JhdGNoNzsKPiDCoH0gX19hdHRyaWJ1dGVfXyAo KHBhY2tlZCkpOwo+IMKgCj4gKy8qCj4gKyAqIEFsbCBiZHMgaW4gb25lIHRyYW5zZmVyIHNob3Vs ZCBiZSBjb25zaXRlbnQgb24gU0RNQS4gVG8gZWFzaWx5IGZvbGxvdyBpdCxqdXN0Cj4gKyAqIHNl dCB0aGUgZG1hIHBvb2wgc2l6ZSBhcyB0aGUgZW5vdWdoIGJkcy4gRm9yIGV4YW1wbGUsIGluIGRt YXRlc3QgY2FzZSwgdGhlCj4gKyAqIG1heCAyMCBiZHMgbWVhbnMgdGhlIG1heCBmb3Igc2luZ2xl IHRyYW5zZmVyIGlzIE5VTV9CRCAqIFNETUFfQkRfTUFYX0NOVCA9IDIwCj4gKyAqICogNjU1MzUg PSB+MS4yOE1CLiAyMCBiZHMgc3VwcG9zZWQgdG8gYmUgZW5vdWdoIGJhc2ljYWxseS5JZiBpdCdz IHN0aWxsIG5vdAo+ICsgKiBlbm91Z2ggaW4gc29tZSBzcGVjaWZpYyBjYXNlcywgZW5sYXJnZSBp dCBoZXJlLldhcm5pbmcgbWVzc2FnZSB3b3VsZCBhbHNvCj4gKyAqIGFwcGVhciBpZiB0aGUgYmQg bnVtYmVycyBpcyBvdmVyIHRoYW4gMjAuCj4gKyAqLwo+ICsjZGVmaW5lIE5VTV9CRCAyMAo+IMKg Cj4gwqBzdHJ1Y3Qgc2RtYV9lbmdpbmU7Cj4gwqAKPiBAQCAtMTI3Myw3ICsxMjgyLDcgQEAgc3Rh dGljIGludCBzZG1hX2FsbG9jX2NoYW5fcmVzb3VyY2VzKHN0cnVjdCBkbWFfY2hhbiAqY2hhbikK PiA+IMKgCQlnb3RvIGRpc2FibGVfY2xrX2FoYjsKPiDCoAo+ID4gwqAJc2RtYWMtPmJkX3Bvb2wg PSBkbWFfcG9vbF9jcmVhdGUoImJkX3Bvb2wiLCBjaGFuLT5kZXZpY2UtPmRldiwKPiA+IC0JCQkJ c2l6ZW9mKHN0cnVjdCBzZG1hX2J1ZmZlcl9kZXNjcmlwdG9yKSwKPiA+ICsJCQkJTlVNX0JEICog c2l6ZW9mKHN0cnVjdCBzZG1hX2J1ZmZlcl9kZXNjcmlwdG9yKSwKPiA+IMKgCQkJCTMyLCAwKTsK PiDCoAo+ID4gwqAJcmV0dXJuIDA7Cj4gQEAgLTEzMTQsNiArMTMyMywxMiBAQCBzdGF0aWMgc3Ry dWN0IHNkbWFfZGVzYyAqc2RtYV90cmFuc2Zlcl9pbml0KHN0cnVjdCBzZG1hX2NoYW5uZWwgKnNk bWFjLAo+IMKgewo+ID4gwqAJc3RydWN0IHNkbWFfZGVzYyAqZGVzYzsKPiDCoAo+ID4gKwlpZiAo YmRzID4gTlVNX0JEKSB7Cj4gPiArCQlkZXZfZXJyKHNkbWFjLT5zZG1hLT5kZXYsICIlZCBiZHMg ZXhjZWVkIHRoZSBtYXggJWRcbiIsCj4gPiArCQkJYmRzLCBOVU1fQkQpOwo+ID4gKwkJZ290byBl cnJfb3V0Owo+ID4gKwl9Cj4gKwo+ID4gwqAJZGVzYyA9IGt6YWxsb2MoKHNpemVvZigqZGVzYykp LCBHRlBfTk9XQUlUKTsKPiA+IMKgCWlmICghZGVzYykKPiA+IMKgCQlnb3RvIGVycl9vdXQ7Ci0t LQpUbyB1bnN1YnNjcmliZSBmcm9tIHRoaXMgbGlzdDogc2VuZCB0aGUgbGluZSAidW5zdWJzY3Jp YmUgZG1hZW5naW5lIiBpbgp0aGUgYm9keSBvZiBhIG1lc3NhZ2UgdG8gbWFqb3Jkb21vQHZnZXIu a2VybmVsLm9yZwpNb3JlIG1ham9yZG9tbyBpbmZvIGF0ICBodHRwOi8vdmdlci5rZXJuZWwub3Jn L21ham9yZG9tby1pbmZvLmh0bWwK From mboxrd@z Thu Jan 1 00:00:00 1970 From: l.stach@pengutronix.de (Lucas Stach) Date: Mon, 23 Jul 2018 12:54:12 +0200 Subject: [PATCH v3 3/3] dmaengine: imx-sdma: allocate max 20 bds for one transfer In-Reply-To: <1532367972-29707-4-git-send-email-yibin.gong@nxp.com> References: <1532367972-29707-1-git-send-email-yibin.gong@nxp.com> <1532367972-29707-4-git-send-email-yibin.gong@nxp.com> Message-ID: <1532343252.3163.99.camel@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Am Dienstag, den 24.07.2018, 01:46 +0800 schrieb Robin Gong: > If multi-bds used in one transfer, all bds should be consisten > memory.To easily follow it, enlarge the dma pool size into 20 bds, > and it will report error if the number of bds is over than 20. For > dmatest, the max count for single transfer is NUM_BD * > SDMA_BD_MAX_CNT = 20 * 65535 = ~1.28MB. Both the commit message and the comment need a lot more care to actually tell what this commit is trying to achieve. Currently I don't follow at all. What does "consisten" mean? Do you mean BDs should be contiguous in memory? What do you gain by over-allocating each BD by a factor of 20? Regards, Lucas > Signed-off-by: Robin Gong > --- > ?drivers/dma/imx-sdma.c | 17 ++++++++++++++++- > ?1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c > index b4ec2d2..5973489 100644 > --- a/drivers/dma/imx-sdma.c > +++ b/drivers/dma/imx-sdma.c > @@ -298,6 +298,15 @@ struct sdma_context_data { > > ? u32??scratch7; > ?} __attribute__ ((packed)); > ? > +/* > + * All bds in one transfer should be consitent on SDMA. To easily follow it,just > + * set the dma pool size as the enough bds. For example, in dmatest case, the > + * max 20 bds means the max for single transfer is NUM_BD * SDMA_BD_MAX_CNT = 20 > + * * 65535 = ~1.28MB. 20 bds supposed to be enough basically.If it's still not > + * enough in some specific cases, enlarge it here.Warning message would also > + * appear if the bd numbers is over than 20. > + */ > +#define NUM_BD 20 > ? > ?struct sdma_engine; > ? > @@ -1273,7 +1282,7 @@ static int sdma_alloc_chan_resources(struct dma_chan *chan) > > ? goto disable_clk_ahb; > ? > > ? sdmac->bd_pool = dma_pool_create("bd_pool", chan->device->dev, > > - sizeof(struct sdma_buffer_descriptor), > > + NUM_BD * sizeof(struct sdma_buffer_descriptor), > > ? 32, 0); > ? > > ? return 0; > @@ -1314,6 +1323,12 @@ static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac, > ?{ > > ? struct sdma_desc *desc; > ? > > + if (bds > NUM_BD) { > > + dev_err(sdmac->sdma->dev, "%d bds exceed the max %d\n", > > + bds, NUM_BD); > > + goto err_out; > > + } > + > > ? desc = kzalloc((sizeof(*desc)), GFP_NOWAIT); > > ? if (!desc) > > ? goto err_out; From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC3F7ECDE5F for ; Mon, 23 Jul 2018 10:54:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 884CF20854 for ; Mon, 23 Jul 2018 10:54:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 884CF20854 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387937AbeGWLy7 (ORCPT ); Mon, 23 Jul 2018 07:54:59 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:33395 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387830AbeGWLy7 (ORCPT ); Mon, 23 Jul 2018 07:54:59 -0400 Received: from kresse.hi.pengutronix.de ([2001:67c:670:100:1d::2a]) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1fhYTm-0002BQ-Hy; Mon, 23 Jul 2018 12:54:14 +0200 Message-ID: <1532343252.3163.99.camel@pengutronix.de> Subject: Re: [PATCH v3 3/3] dmaengine: imx-sdma: allocate max 20 bds for one transfer From: Lucas Stach To: Robin Gong , vkoul@kernel.org, dan.j.williams@intel.com, s.hauer@pengutronix.de, linux@armlinux.org.uk Cc: dmaengine@vger.kernel.org, linux-imx@nxp.com, kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Date: Mon, 23 Jul 2018 12:54:12 +0200 In-Reply-To: <1532367972-29707-4-git-send-email-yibin.gong@nxp.com> References: <1532367972-29707-1-git-send-email-yibin.gong@nxp.com> <1532367972-29707-4-git-send-email-yibin.gong@nxp.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::2a X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Dienstag, den 24.07.2018, 01:46 +0800 schrieb Robin Gong: > If multi-bds used in one transfer, all bds should be consisten > memory.To easily follow it, enlarge the dma pool size into 20 bds, > and it will report error if the number of bds is over than 20. For > dmatest, the max count for single transfer is NUM_BD * > SDMA_BD_MAX_CNT = 20 * 65535 = ~1.28MB. Both the commit message and the comment need a lot more care to actually tell what this commit is trying to achieve. Currently I don't follow at all. What does "consisten" mean? Do you mean BDs should be contiguous in memory? What do you gain by over-allocating each BD by a factor of 20? Regards, Lucas > Signed-off-by: Robin Gong > --- >  drivers/dma/imx-sdma.c | 17 ++++++++++++++++- >  1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c > index b4ec2d2..5973489 100644 > --- a/drivers/dma/imx-sdma.c > +++ b/drivers/dma/imx-sdma.c > @@ -298,6 +298,15 @@ struct sdma_context_data { > >   u32  scratch7; >  } __attribute__ ((packed)); >   > +/* > + * All bds in one transfer should be consitent on SDMA. To easily follow it,just > + * set the dma pool size as the enough bds. For example, in dmatest case, the > + * max 20 bds means the max for single transfer is NUM_BD * SDMA_BD_MAX_CNT = 20 > + * * 65535 = ~1.28MB. 20 bds supposed to be enough basically.If it's still not > + * enough in some specific cases, enlarge it here.Warning message would also > + * appear if the bd numbers is over than 20. > + */ > +#define NUM_BD 20 >   >  struct sdma_engine; >   > @@ -1273,7 +1282,7 @@ static int sdma_alloc_chan_resources(struct dma_chan *chan) > >   goto disable_clk_ahb; >   > >   sdmac->bd_pool = dma_pool_create("bd_pool", chan->device->dev, > > - sizeof(struct sdma_buffer_descriptor), > > + NUM_BD * sizeof(struct sdma_buffer_descriptor), > >   32, 0); >   > >   return 0; > @@ -1314,6 +1323,12 @@ static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac, >  { > >   struct sdma_desc *desc; >   > > + if (bds > NUM_BD) { > > + dev_err(sdmac->sdma->dev, "%d bds exceed the max %d\n", > > + bds, NUM_BD); > > + goto err_out; > > + } > + > >   desc = kzalloc((sizeof(*desc)), GFP_NOWAIT); > >   if (!desc) > >   goto err_out;