Return-path: Received: from mx1.redhat.com ([209.132.183.28]:47683 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751761AbcAEPxh (ORCPT ); Tue, 5 Jan 2016 10:53:37 -0500 From: Jes Sorensen To: Julian Calaby Cc: Sven Dziadek , Larry Finger , Greg KH , linux-wireless , "devel\@driverdev.osuosl.org" , "linux-kernel\@vger.kernel.org" Subject: Re: [RFC PATCH] staging: rtl8723au: fix byte order problems References: <1451921374-471-1-git-send-email-sven.dziadek@gmx.de> Date: Tue, 05 Jan 2016 10:53:36 -0500 In-Reply-To: (Julian Calaby's message of "Tue, 5 Jan 2016 08:57:56 +1100") Message-ID: (sfid-20160105_165356_355514_DBA22E80) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: Julian Calaby writes: > Hi Sven, > > On Tue, Jan 5, 2016 at 2:29 AM, Sven Dziadek wrote: >> diff --git a/drivers/staging/rtl8723au/hal/rtl8723a_cmd.c b/drivers/staging/rtl8723au/hal/rtl8723a_cmd.c >> index 1662c03c..57f5941 100644 >> --- a/drivers/staging/rtl8723au/hal/rtl8723a_cmd.c >> +++ b/drivers/staging/rtl8723au/hal/rtl8723a_cmd.c >> @@ -93,11 +93,9 @@ int FillH2CCmd(struct rtw_adapter *padapter, u8 ElementID, u32 CmdLen, >> >> if (h2c_cmd & BIT(7)) { >> msgbox_ex_addr = REG_HMEBOX_EXT_0 + (h2c_box_num * EX_MESSAGE_BOX_SIZE); >> - h2c_cmd_ex = le16_to_cpu(h2c_cmd_ex); >> rtl8723au_write16(padapter, msgbox_ex_addr, h2c_cmd_ex); >> } >> msgbox_addr = REG_HMEBOX_0 + (h2c_box_num * MESSAGE_BOX_SIZE); >> - h2c_cmd = le32_to_cpu(h2c_cmd); >> rtl8723au_write32(padapter, msgbox_addr, h2c_cmd); > > While Jes has NACK'd this change, it does highlight that the h2c_cmd > and h2c_cmd_ex variables are being used to hold both cpu-endian and > little-endian data. A worthwhile change here might be to move the > conversion into the function call following these lines so that they > remain "clean". > > That said, I'm not sure this particular snippet of code would work on > big-endian at all as I'm pretty sure that BIT() produces cpu-endian > values and we know from the line you remove that h2c_cmd is > little-endian at this point. I am not opposed to cleaning it up, however I hope we can just remove all of the code down the line instead. You may want to look at the h2c implementation I did for rtl8xxxu. I believe it does work on big-endian, at least I know Larry has been able to test it on big-endian systems. Cheers, Jes