>-----Original Message----- >From: Anand Gadiyar [mailto:gadiyar@xxxxxx] >Sent: Thursday, November 25, 2010 6:13 PM >To: balbi@xxxxxx; Bob Liu >Cc: Zhang, Sonic; Mike Frysinger; >uclinux-dist-devel@xxxxxxxxxxxxxxxxxxxx; Ajay Kumar Gupta; >linux-usb@xxxxxxxxxxxxxxx >Subject: RE: [PATCH] musb_host: Fix high bandwidth iso transfer issue > >Felipe Balbi wrote: >> Hi, >> >> On Thu, Nov 25, 2010 at 04:54:05PM +0800, Bob Liu wrote: >> >>> The only work around is to config the receive FIFO into single >buffer >> >>> mode. >> >> >> >> And how to do that ? >> >> >> > >> >It's used to by "USB: musb: disable double buffering for older RTL >> >versions" >> >>http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git; >a=commitd >>if >f;h=9f445cb29918dc488b7a9a92ef018599cce33df7 >> >> yeah, but that breaks other stuff high bandwidth eps, so we need a >> better way to "disable double buffering". >> > >Here's how I understand the problem. > >Blackfin has a statically configured fifo allocation - with no >possibility to change it. The IP uses double buffering by >default if a FIFO is allocated space enough to hold 2*maxp >(which is the case for at least some of the endpoints). > >The only way to make the IP use single buffering is to tell >the IP that the maxp is different. > >This is an anomaly only in the blackfin - I don't see any way >to work around this (for lack of information), than what has >been implemented in the patch that already got merged. > >However, that code should be made to execute only on blackfin >and not on other platforms - so that the others are not broken >by that change. > >Is this a fair summary? > Hi Anand, Perfect summary. Then, how about replacing the hardware version checking with BLACKFIN arch checking in original patch? Sonic >- Anand > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
