On Fri, Jan 03, 2014 at 09:03:11PM -0800, Andrey Smirnov wrote: > On Fri, Jan 3, 2014 at 8:44 PM, Dmitry Torokhov > <dmitry.torokhov@xxxxxxxxx> wrote: > > On Fri, Jan 03, 2014 at 08:24:17PM -0800, Andrey Smirnov wrote: > >> On Fri, Jan 3, 2014 at 5:39 PM, Dmitry Torokhov > >> <dmitry.torokhov@xxxxxxxxx> wrote: > >> > Hi Andrey, > >> > > >> > On Wed, Jan 01, 2014 at 04:47:01PM -0800, Andrey Smirnov wrote: > >> >> New version of the PCU firmware supports two new commands: > >> >> - IMS_PCU_CMD_OFN_SET_CONFIG which allows to write data to the > >> >> registers of one finger navigation(OFN) chip present on the device > >> >> - IMS_PCU_CMD_OFN_GET_CONFIG which allows to read data form the > >> >> registers of said chip. > >> >> > >> >> This commit adds two helper functions to use those commands and sysfs > >> >> attributes to use them. It also exposes some OFN configuration > >> >> parameters via sysfs. > >> > > >> > Thank you for making the changes. I do not still quite like the games we > >> > play with the OFN attributes, how about the patch below (on top of > >> > yours)? > >> > > >> > >> Yeah, I agree I like it the "two separate sysfs groups" group approach > >> better. The only small nitpick about your patch is that I think we > >> should use "get_unaligned_le16" instead of "le16_to_cpup"(In case > >> anyone decides to run the driver on SuperH or C6x DSPs from TI :-)). > >> Let me test it and if everything works as expected I'll apply you > >> patch, convert it to "get_unaligned_le16", squash and send v3 of the > >> patch. > > > > Why do we need get_unaligned_le16()? As far as I can see pcu->cmd_buf is > > aligned and therefore pcu->cmd_buf[2] is also aligned on word boundary. > > * The "pcu" structure is allocated with kmalloc which doesn't give any > guarantees about address alignment. > * I am not sure if the cmd_buf field in that structure is aligned, and > even if it is, any future changes to that structure may shift its > offset. > * Also even if the data we are interested in is aligned on 2-byte > border, I think all those architectures require 4-byte border > alignment. As far as I know word access only requires word alignment. Please see the other patch I just posted that adds alignment check in balcklight handling code. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
