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Groups > linux.kernel > #1617916
| From | Ludovic Desroches <ludovic.desroches@microchip.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 4.4 42/76] mmc: sdhci: Do not disable interrupts while waiting for clock |
| Date | 2017-04-06 14:20 +0200 |
| Message-ID | <tteyl-8ob-19@gated-at.bofh.it> (permalink) |
| References | <tpYzL-7we-3@gated-at.bofh.it> <tpYzM-7we-21@gated-at.bofh.it> <tszYd-7uN-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Apr 04, 2017 at 05:50:50PM +0100, Ben Hutchings wrote: > On Tue, 2017-03-28 at 14:30 +0200, Greg Kroah-Hartman wrote: > > 4.4-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Adrian Hunter <adrian.hunter@intel.com> > > > > commit e2ebfb2142acefecc2496e71360f50d25726040b upstream. > > > > Disabling interrupts for even a millisecond can cause problems for some > > devices. That can happen when sdhci changes clock frequency because it > > waits for the clock to become stable under a spin lock. > > > > The spin lock is not necessary here. Anything that is racing with changes > > to the I/O state is already broken. The mmc core already provides > > synchronization via "claiming" the host. > [...] > > In mainline, drivers/mmc/host/sdhci-of-at91.c has a slightly different > version of this code that seems to have the same issue. In 4.4 there's > another (conditional) mdelay(1) further up this function that seems to > be related to that hardware, and probably ought to have an unlock/lock > around it. Right, how do you want to proceed? Do you want me to send a patch on top of it to manage this extra mdelay? Regards Ludovic
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[PATCH 4.4 42/76] mmc: sdhci: Do not disable interrupts while waiting for clock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-28 14:40 +0200
Re: [PATCH 4.4 42/76] mmc: sdhci: Do not disable interrupts while waiting for clock Ben Hutchings <ben.hutchings@codethink.co.uk> - 2017-04-04 19:00 +0200
Re: [PATCH 4.4 42/76] mmc: sdhci: Do not disable interrupts while waiting for clock Ludovic Desroches <ludovic.desroches@microchip.com> - 2017-04-06 14:20 +0200
Re: [PATCH 4.4 42/76] mmc: sdhci: Do not disable interrupts while waiting for clock Ben Hutchings <ben.hutchings@codethink.co.uk> - 2017-04-06 16:30 +0200
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