linux-kernel - Re: [PATCH 1/2] mfd: rtsx: add func to split u32 into register

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 28 Nov 2014 09:54:07 +0000
From:	敬锐 <micky_ching@...lsil.com.cn>
To:	Dan Carpenter <dan.carpenter@...cle.com>
CC:	"sameo@...ux.intel.com" <sameo@...ux.intel.com>,
	"lee.jones@...aro.org" <lee.jones@...aro.org>,
	"chris@...ntf.net" <chris@...ntf.net>,
	"ulf.hansson@...aro.org" <ulf.hansson@...aro.org>,
	"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
	"linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	王炜 <wei_wang@...lsil.com.cn>,
	"rogerable@...ltek.com" <rogerable@...ltek.com>,
	"devel@...uxdriverproject.org" <devel@...uxdriverproject.org>
Subject: Re: [PATCH 1/2] mfd: rtsx: add func to split u32 into register

Let's take an example,

cmd.arg = ((ocr & 0xFF8000) != 0) << 8 | test_pattern;

using "TP" name test_pattern for simplication ,
when we call: rtsx_pci_write_be32(pcr, SD_CMD1, cmd->arg);
we should make sure TP write to SD_CMD4.

If on "be" platform, then cpu_to_be32() do nothing,
and TP is write to SD_CMD1, in this case, it is wrong.

BR,
micky.
On 11/27/2014 11:23 PM, Dan Carpenter wrote:
> On Thu, Nov 27, 2014 at 10:53:58AM +0800, micky_ching@...lsil.com.cn wrote:
>> +static inline void rtsx_pci_write_be32(struct rtsx_pcr *pcr, u16 reg, u32 val)
>> +{
>> +	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg,     0xFF, val >> 24);
>> +	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 1, 0xFF, val >> 16);
>> +	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 2, 0xFF, val >> 8);
>> +	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 3, 0xFF, val);
> This assumes the cpu is little endian.  First convert to big endian
> using cpu_to_be32() and then write it out.
>
> 	__be32 be_val = cpu_to_be32()
>
> 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg,     0xFF, be_val);
> 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 1, 0xFF, be_val >> 8);
> 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 2, 0xFF, be_val >> 16);
> 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 3, 0xFF, be_val >> 24);
>
> (Written hurredly in my mail client.  May be wrong).
>
>> +}
>> +
>> +static inline void rtsx_pci_write_le32(struct rtsx_pcr *pcr, u16 reg, u32 val)
>> +{
>> +	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg,     0xFF, val);
>> +	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 1, 0xFF, val >> 8);
>> +	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 2, 0xFF, val >> 16);
>> +	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, reg + 3, 0xFF, val >> 24);
>> +}
> We don't have a user for rtsx_pci_write_le32() so don't add it.
>
> regards,
> dan carpenter