From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huang Shijie Subject: Re: [PATCH 2/3] serial: mxs: enable the DMA only when the rts/cts is enabled Date: Mon, 15 Jul 2013 16:41:25 +0800 Message-ID: <51E3B5B5.1030706@freescale.com> References: <1373857736-30108-1-git-send-email-b32955@freescale.com> <1373857736-30108-2-git-send-email-b32955@freescale.com> <20130715082716.GM12139@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20130715082716.GM12139@pengutronix.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: =?UTF-8?B?VXdlIEtsZWluZS1Lw7ZuaWc=?= Cc: gregkh@linuxfoundation.org, shawn.guo@linaro.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-serial@vger.kernel.org 5LqOIDIwMTPlubQwN+aciDE15pelIDE2OjI3LCBVd2UgS2xlaW5lLUvDtm5pZyDlhpnpgZM6Cj4g ZG8geW91IHdhbnQgdG8gc2F5IHRoYXQgdGhlIGRyaXZlciBmYWlscyB0byBvbmx5IGVuYWJsZSBE TUEgd2hlbiBSVFMvQ1RTCj4gYXJlIGF2YWlsYWJsZTsgb3IgdGhhdCB0b2RheSB0aGUgZHJpdmVy IGNhbiBoYW5kbGUgRE1BIGp1c3QgZmluZSBldmVuCj4gd2l0aG91dCBSVFMvQ1RTPyBJIGludGVy cHJldCB5b3VyIGNvbW1pdCBsb2cgYXMgdGhlIGxhdHRlciwgeW91ciBwYXRjaAo+IGltcGxlbWVu dHMgdGhlIGZvcm1lciBob3dldmVyLgppbiB0aGUgbXhzLWF1YXJ0LCBpZiB0aGUgUlRTL0NUUyBp cyBub3QgaW52YWxpZCwgdGhlIERNQSBzaG91bGQgYmUgbm90IAplbmFibGVkLgoKQnV0IGN1cnJl bnQgY29kZSBsb3N0IHRoZSBsaW1pdCwgYSB1YXJ0IHdpdGhvdXQgdGhlIFJUUy9DVFMgbWF5IGFs c28gCmVuYWJsZXMgdGhlIERNQSBpbiB3aGljaCBjYXNlIHRoZSB1YXJ0Cm1heSBkb2VzIG5vdCBy dW4gb3IgcnVuIGluIGEgYWJub3JtYWwgd2F5LgoKdGhhbmtzCkh1YW5nIFNoaWppZQoKCgoKCl9f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmxpbnV4LWFybS1r ZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4LWFybS1rZXJuZWxAbGlzdHMuaW5mcmFkZWFkLm9yZwpo dHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LWFybS1rZXJu ZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 From: b32955@freescale.com (Huang Shijie) Date: Mon, 15 Jul 2013 16:41:25 +0800 Subject: [PATCH 2/3] serial: mxs: enable the DMA only when the rts/cts is enabled In-Reply-To: <20130715082716.GM12139@pengutronix.de> References: <1373857736-30108-1-git-send-email-b32955@freescale.com> <1373857736-30108-2-git-send-email-b32955@freescale.com> <20130715082716.GM12139@pengutronix.de> Message-ID: <51E3B5B5.1030706@freescale.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org ? 2013?07?15? 16:27, Uwe Kleine-K?nig ??: > do you want to say that the driver fails to only enable DMA when RTS/CTS > are available; or that today the driver can handle DMA just fine even > without RTS/CTS? I interpret your commit log as the latter, your patch > implements the former however. in the mxs-auart, if the RTS/CTS is not invalid, the DMA should be not enabled. But current code lost the limit, a uart without the RTS/CTS may also enables the DMA in which case the uart may does not run or run in a abnormal way. thanks Huang Shijie