Return-path: Received: from wf-out-1314.google.com ([209.85.200.171]:21768 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752440AbZBFHrj (ORCPT ); Fri, 6 Feb 2009 02:47:39 -0500 MIME-Version: 1.0 In-Reply-To: <1233846195.3028.14.camel@localhost> References: <1233819002-6912-1-git-send-email-cooloney@kernel.org> <1233846195.3028.14.camel@localhost> Date: Fri, 6 Feb 2009 15:47:38 +0800 Message-ID: <386072610902052347m5754262bif18339809a00cb9f@mail.gmail.com> (sfid-20090206_084746_144312_674B23D8) Subject: Re: [PATCH] wireless: introduce POWEROF2_BLOCKSIZE_ONLY option From: Bryan Wu To: Dan Williams Cc: linville@tuxdriver.com, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Cliff Cai Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Feb 5, 2009 at 11:03 PM, Dan Williams wrote: > On Thu, 2009-02-05 at 15:30 +0800, Bryan Wu wrote: >> From: Cliff Cai >> >> Introduce POWEROF2_BLOCKSIZE_ONLY option for those SD/SDIO host >> which only support transferring block with size of power-of-2 > > Is the point here to avoid copying in the controller code? As with the > other patches on libertas-dev, I really dislike adding code to *every > SDIO driver* just because the host has certain restrictions. I'd much > rather that the host/controller code became aware of it's own > restrictions, and exposed those generically to drivers above it. > Without a KConfig option. > > Seriously. The host knows what it needs. The code to handle that > should go in the host. > I agree here. > How about adding a method like "sdio_align_size" that takes the > controller's constraints into account? That seems a lot cleaner than > adding #define/KConfig junk to every SDIO driver in the kernel. One > less codepath to test, makes your life and all our lives easier. > So we plan to add method ".sdio_align_size" to SDIO stack. And Blackfin host driver will implement this method while others will implement this as a dummy function. In libertas, we need to call this method to take this constraints into account. Thanks -Bryan >> [ Bryan Wu : >> - remove some useless coding style cleanup >> - using roundup() function as upstream does >> ] >> >> Signed-off-by: Cliff Cai >> Signed-off-by: Bryan Wu >> --- >> drivers/net/wireless/Kconfig | 6 ++++++ >> drivers/net/wireless/libertas/if_sdio.c | 16 ++++++++++++++++ >> 2 files changed, 22 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/net/wireless/Kconfig b/drivers/net/wireless/Kconfig >> index e4f9f74..a2685fa 100644 >> --- a/drivers/net/wireless/Kconfig >> +++ b/drivers/net/wireless/Kconfig >> @@ -151,6 +151,12 @@ config LIBERTAS_SDIO >> ---help--- >> A driver for Marvell Libertas 8385 and 8686 SDIO devices. >> >> +config POWEROF2_BLOCKSIZE_ONLY >> + bool "Support transferring block with size of power-of-2 only" >> + depends on LIBERTAS_SDIO >> + ---help--- >> + For SD/SDIO host which only supports transferring block with size of power-of-2. >> + >> config LIBERTAS_DEBUG >> bool "Enable full debugging output in the Libertas module." >> depends on LIBERTAS >> diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c >> index 4519d73..5efc056 100644 >> --- a/drivers/net/wireless/libertas/if_sdio.c >> +++ b/drivers/net/wireless/libertas/if_sdio.c >> @@ -272,6 +272,11 @@ static int if_sdio_card_to_host(struct if_sdio_card *card) >> */ >> chunk = sdio_align_size(card->func, size); >> >> +/* For SD/SDIO host which only supports transferring block with size of power-of-2 */ >> +#if defined(CONFIG_POWEROF2_BLOCKSIZE_ONLY) >> + chunk = (chunk + card->func->cur_blksize - 1) / >> + card->func->cur_blksize * card->func->cur_blksize; >> +#endif >> ret = sdio_readsb(card->func, card->buffer, card->ioport, chunk); >> if (ret) >> goto out; >> @@ -581,8 +586,14 @@ static int if_sdio_prog_real(struct if_sdio_card *card) >> lbs_deb_sdio("sending %d bytes (%d bytes) chunk\n", >> chunk_size, (chunk_size + 31) / 32 * 32); >> */ >> +/* For SD/SDIO host which only supports transferring block with size of power-of-2 */ >> +#if defined(CONFIG_POWEROF2_BLOCKSIZE_ONLY) >> + ret = sdio_writesb(card->func, card->ioport, >> + chunk_buffer, roundup(chunk_size, 256); >> +#else >> ret = sdio_writesb(card->func, card->ioport, >> chunk_buffer, roundup(chunk_size, 32)); >> +#endif >> if (ret) >> goto release; >> >> @@ -699,6 +710,11 @@ static int if_sdio_host_to_card(struct lbs_private *priv, >> */ >> size = sdio_align_size(card->func, nb + 4); >> >> +/* For SD/SDIO host which only supports transferring block with size of power-of-2 */ >> +#if defined(CONFIG_POWEROF2_BLOCKSIZE_ONLY) >> + size = (size + card->func->cur_blksize - 1) / >> + card->func->cur_blksize * card->func->cur_blksize; >> +#endif >> packet = kzalloc(sizeof(struct if_sdio_packet) + size, >> GFP_ATOMIC); >> if (!packet) { > >