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. > > 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
