* Re: [PATCH] soc: fsl/qe: fix Oops on CPM1 (and likely CPM2) [not found] <20160808160858.4B9251A2452@localhost.localdomain> @ 2016-08-11 23:29 ` Scott Wood 2016-08-12 6:25 ` Christophe Leroy 0 siblings, 1 reply; 2+ messages in thread From: Scott Wood @ 2016-08-11 23:29 UTC (permalink / raw) To: Christophe Leroy, Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, Zhao Qiang, David S.Miller Cc: linux-kernel, linuxppc-dev, stable On Mon, 2016-08-08 at 18:08 +0200, Christophe Leroy wrote: > Commit 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram") > has changed the way muram is managed. > genalloc uses kmalloc(), hence requires the SLAB to be up and running. > > On powerpc 8xx, cpm_reset() is called early during startup. > cpm_reset() then calls cpm_muram_init() before SLAB is available, > hence the following Oops. > > cpm_reset() cannot be called during initcalls because the CPM is > needed for console > > This patch splits cpm_muram_init() in two parts. The first part, > related to mappings, is kept as cpm_muram_init() > The second part is named cpm_muram_pool_init() and is called > the first time cpm_muram_alloc() is used Why do you need to split it, versus calling the full cpm_muram_init() on demand? -Scott ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] soc: fsl/qe: fix Oops on CPM1 (and likely CPM2) 2016-08-11 23:29 ` [PATCH] soc: fsl/qe: fix Oops on CPM1 (and likely CPM2) Scott Wood @ 2016-08-12 6:25 ` Christophe Leroy 0 siblings, 0 replies; 2+ messages in thread From: Christophe Leroy @ 2016-08-12 6:25 UTC (permalink / raw) To: Scott Wood, Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, Zhao Qiang, David S.Miller Cc: linux-kernel, linuxppc-dev, stable Le 12/08/2016 à 01:29, Scott Wood a écrit : > On Mon, 2016-08-08 at 18:08 +0200, Christophe Leroy wrote: >> Commit 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram") >> has changed the way muram is managed. >> genalloc uses kmalloc(), hence requires the SLAB to be up and running. >> >> On powerpc 8xx, cpm_reset() is called early during startup. >> cpm_reset() then calls cpm_muram_init() before SLAB is available, >> hence the following Oops. >> >> cpm_reset() cannot be called during initcalls because the CPM is >> needed for console >> >> This patch splits cpm_muram_init() in two parts. The first part, >> related to mappings, is kept as cpm_muram_init() >> The second part is named cpm_muram_pool_init() and is called >> the first time cpm_muram_alloc() is used > > Why do you need to split it, versus calling the full cpm_muram_init() on > demand? > There are drivers like for instance de i2c-cpm driver, that for instance call cpm_muram_addr() before calling cpm_muram_alloc() Therefore, we need muram_vbase and muram_pbase set. So if we want to keep a single function, it means we also have to call it on demand from cpm_muram_addr(), cpm_muram_offset() and cpm_muram_dma(). Is that what you recommend ? Christophe ^ permalink raw reply [flat|nested] 2+ messages in thread
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2016-08-11 23:29 ` [PATCH] soc: fsl/qe: fix Oops on CPM1 (and likely CPM2) Scott Wood
2016-08-12 6:25 ` Christophe Leroy
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