From mboxrd@z Thu Jan 1 00:00:00 1970 From: jszhang@marvell.com (Jisheng Zhang) Date: Sat, 10 Oct 2015 15:05:35 +0800 Subject: [PATCH v2 2/5] mmc: sdhci-pxav3: enable usage of DAT3 pin as HW card detect In-Reply-To: References: <1444352635-21965-1-git-send-email-mw@semihalf.com> <1444352635-21965-3-git-send-email-mw@semihalf.com> <20151009201356.78488116@xhacker> Message-ID: <20151010150535.6047dab9@xhacker> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Marcin, On Fri, 9 Oct 2015 16:45:25 +0200 Marcin Wojtas wrote: > Jisheng, > > > >> > >> When using DAT3-based detection Armada 38x SDIO IP expects its internal > >> clock to be always on, which had to be ensured twofold: > > > > What happen if runtime suspend disables its core clk and axi clk? I guess > > dat3-based detection isn't compatible with runtime pm. If so, do we also > > need to disable runtime pm in probe function? > > Is runtime resume supposed to be triggered by card detection? Is there I think so. Take marvell berlin for example, card insert => gpio interrupt or => sdhci runtime resume. > a way to manually trigger runtime suspend and resume of sdhci? Anyway If runtime-pm is builtin and the host driver supports runtime-pm (sdhci-pxav3 supports runtime-pm well), when there's no sdhc transactions, runtime suspend will be triggered automatically after some time (50ms?) > coreclk is not a problem, as it's not used by A38x. I checked A38x dts files, it's <&gateclk 17>. So the question is: what will happen if <&gateclk 17> is disabled in runtime suspend? Is the dat3-based CD still works? In theory, it should not work any more. > > > > >> - Each time controller is reset by updating appropriate registers. On the > >> occasion of adding new register @0x104, register @0x100 name is modified > >> in order to the be aligned with Armada 38x documentation. > >> - Leaving the clock enabled despite power-down. For this purpose a new > >> quirk had to be added to SDHCI subsystem - SDHCI_QUIRK2_KEEP_INT_CLK_ON. > > > > As seen from other mails, Ulf calls for no more quirks... > > > > Ok, I'll try to find another solution. > > Best regards, > Marcin