From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: serial on omap in current git. Date: Mon, 13 Feb 2006 10:23:57 -0800 Message-ID: <20060213182357.GA5113@atomide.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-omap-open-source-bounces@linux.omap.com Errors-To: linux-omap-open-source-bounces@linux.omap.com To: "Woodruff, Richard" Cc: Linux-omap-open-source@linux.omap.com List-Id: linux-omap@vger.kernel.org Hi, * Woodruff, Richard [060212 14:15]: > Actually it is more like this... > > > if (up->port.type != PORT_16750) { > if (fcr & UART_FCR_ENABLE_FIFO) { > /* emulated UARTs (Lucent Venus 167x) need two steps */ > serial_outp(up, UART_FCR, UART_FCR_ENABLE_FIFO); > } > if(uart_config[up->port.type].flags & UART_CAP_EFR){ > serial_outp(up, UART_LCR, 0xBF); /*allow access to > EFR(vs LCR)*/ > serial_outp(up, UART_EFR, UART_EFR_ECB);/*allow FCR tx > fifo write*/ > serial_outp(up, UART_LCR, 0x0); /* access back to FCR */ > serial_outp(up, UART_FCR, fcr); /* set fcr with possible > TX fifo setting */ > serial_outp(up, UART_LCR, 0xBF); > serial_outp(up, UART_EFR, 0); > serial_outp(up, UART_LCR, cval); /* access back to FCR > */ > } else > serial_outp(up, UART_FCR, fcr); So the extended capabilities bit is needed to write fcr, or else some settings don't get set? > In my build your last serial hack is not necessary anymore either. Looks like patch f5968b37b3ad35b682b574b578843a0361218aff fixed it in the mainline 8250.c: http://kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=f5968b37b3ad35b682b574b578843a0361218aff;hp=620739025b94fe472c845ce013bff62716d3c576 > I played around a bit trying to remove several of them. To use the > actual TX watermark interrupt set at 32bytes required too ugly of a hack > to use (not use OMAP_SCR=0). Can you list the 8250.c issues you've seen? > A minor note is we are still only using 32 bytes of the 64 byte TX fifo > for transmits in the current code. I'm not sure if there is an > application that this matters to. I guess that could help on bluetooth maybe. Regards, Tony