From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Sat, 20 Oct 2012 10:42:37 -0700 Subject: [U-Boot] [PATCH 1/5] input: Use finer grain udelays while waitng for the i8042 keyboard buffer to empty In-Reply-To: <1350004554-18506-1-git-send-email-sjg@chromium.org> References: <1350004554-18506-1-git-send-email-sjg@chromium.org> Message-ID: <20121020174237.GG5854@bill-the-cat> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thu, Oct 11, 2012 at 06:15:49PM -0700, Simon Glass wrote: > From: Gabe Black > > On x86, the i8042 keyboard controller driver frequently waits for the keyboard > input buffer to be empty to make sure the controller has had a chance to > process the data it was given. The way the delay loop was structured, if the > controller hadn't cleared the corresponding status bit immediately, it would > wait 1ms before checking again. If the keyboard responded quickly but not > instantly, the driver would still wait a full 1ms when perhaps 1us would have > been sufficient. Because udelay is a busy wait anyway, this change decreases > the delay between checks to 1us. > > Also, this change gets rid of a hardcoded 250ms delay. > > On Stumpy, this saves 100-150ms during boot. > > Signed-off-by: Gabe Black > Signed-off-by: Simon Glass This, or more precisely, v2 of 1/5 and 2/5 and v1 of 3, 4 and 5/5 have been applied to u-boot/master, thanks! -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: