From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932205AbeCLNee (ORCPT ); Mon, 12 Mar 2018 09:34:34 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:48778 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751242AbeCLNed (ORCPT ); Mon, 12 Mar 2018 09:34:33 -0400 Subject: Re: [PATCH v9] mmc: Export host capabilities to debugfs. To: Andy Shevchenko , Avri Altman , "ulf.hansson@linaro.org" , "linus.walleij@linaro.org" , "adrian.hunter@intel.com" , "shawn.lin@rock-chips.com" CC: "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Vladimir_Zapolskiy@mentor.com" References: <1520829090-3567-1-git-send-email-harish_kandiga@mentor.com> <1520849262.10722.582.camel@linux.intel.com> <540fef96-aa2f-e6c3-467d-bc1d021dd55b@mentor.com> <329d521d-1776-43ee-2f0e-e9690c29a693@mentor.com> <1520859807.10722.591.camel@linux.intel.com> From: Harish Jenny K N Message-ID: <5e038945-a09c-5c64-2152-5d2783a249ec@mentor.com> Date: Mon, 12 Mar 2018 19:04:17 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1520859807.10722.591.camel@linux.intel.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [137.202.0.87] X-ClientProxiedBy: svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 12 March 2018 06:33 PM, Andy Shevchenko wrote: > On Mon, 2018-03-12 at 18:00 +0530, Harish Jenny K N wrote: > > >>>>>>> + for_each_set_bit(bit, (const unsigned long *)&caps, >>>>>>> BITS_PER_LONG) >>>>>>> + for_each_set_bit(bit, (const unsigned long >>>>>>> *)&caps2, >>>>>>> BITS_PER_LONG) >>>>>> Explicit casting is not needed anymore in both cases. >>>>> Also maybe use sizeof(mmc_host_capabilities) instead of >>>>> BITS_PER_LONG? >>>> You mean sizeof(caps) and not sizeof(mmc_host_capabilities) . >>>> Right ? >>> meant ARRAY_SIZE(mmc_host_capabilities) >> ARRAY_SIZE(mmc_host_capabilities) will be 32 and this will be my old >> change for which I got a comment from Andy Shevchenko asking me to >> replace u32 with unsigned long. >> >> This is the old comment: >> >>>> + int size = sizeof(u32) * BITS_PER_BYTE; >>> This is redundant. Use BITS_PER_LONG (why's that, see below) in the > There is nothing about ARRAY_SIZE(). > ARRAY_SIZE() will work quite good as well. Yes. Definitely it works. I was only mentioning about changing u32 to unsigned long for caps and passing BITS_PER_LONG  as size in for_each_set_bit. > >> for_each_set_bit(). >> >>>> + for_each_set_bit(bit, (const unsigned long *)&caps, size) >>>> + for_each_set_bit(bit, (const unsigned long *)&caps2, size) >>> These are UB cases. >>> Fix is simple, replace u32 by unsigned long in (1) above. >> Note: Without typecasting &caps to(const unsigned long *) will give >> compilation error in this case. > What kind of? > Sorry for I was not clear that the compilation error is for the following case > u32 caps = host->caps; > for_each_set_bit(bit, &caps, ARRAY_SIZE(mmc_host_capabilities)) example: compilation for arm gives this error for the following lines: drivers/mmc/core/debugfs.c: In function 'mmc_caps_show': ./include/linux/bitops.h:41:30: error: passing argument 1 of '_find_first_bit_le' from incompatible pointer type [-Werror=incompatible-pointer-types]   for ((bit) = find_first_bit((addr), (size));  \                               ^ ./arch/arm/include/asm/bitops.h:202:50: note: in definition of macro 'find_first_bit'  #define find_first_bit(p,sz)  _find_first_bit_le(p,sz)                                                   ^ drivers/mmc/core/debugfs.c:318:2: note: in expansion of macro 'for_each_set_bit'   for_each_set_bit(bit, &caps, ARRAY_SIZE(mmc_host_capabilities))   ^ ./arch/arm/include/asm/bitops.h:165:12: note: expected 'const long unsigned int *' but argument is of type 'u32 * {aka unsigned int *}'  extern int _find_first_bit_le(const unsigned long *p, unsigned size);             ^ Thanks, Harish Jenny K N