From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Fri, 20 Jul 2012 15:44:01 +0200 Subject: [U-Boot] [PATCH v2 2/5] ehci-hcd: Boost transfer speed In-Reply-To: <96993036.332428.1342790258021.JavaMail.root@advansee.com> References: <96993036.332428.1342790258021.JavaMail.root@advansee.com> Message-ID: <201207201544.01904.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Beno?t Th?baudeau, > On Friday 20 July 2012 13:37:37 Stefan Herbrechtsmeier wrote: > > Am 20.07.2012 13:26, schrieb Beno?t Th?baudeau: > > > + int xfr_bytes = min(left_length, > > > + (QT_BUFFER_CNT * 4096 - > > > + ((uint32_t)buf_ptr & 4095)) & > > > + ~4095); > > > > Why you align the length to 4096? > > It's to guarantee that each transfer length is a multiple of the max packet > length. Otherwise, early short packets are issued, which breaks the > transfer and results in time-out error messages. Early short packets ? What do you mean? > Regards, > Beno?t Best regards, Marek Vasut