On 5/6/19 4:39 PM, Laszlo Ersek wrote: > On 05/05/19 22:05, Philippe Mathieu-Daudé wrote: >> The 'CFI01' NOR flash was introduced in commit 29133e9a0fff, with >> timing modelled. One year later, the CFI02 model was introduced >> (commit 05ee37ebf630) based on the CFI01 model. As noted in the > > You got those commit references backwards, I believe: > > * Commit 29133e9a0fff ("AMD NOR flash device support (initial patch by > Jocelyn Mayer)", 2006-06-25) introduced "hw/pflash_cfi02.c". > > * Commit 05ee37ebf630 ("Gumstix 'connex' board support by Thorsten > Zitterell.", 2007-11-17) introduced "hw/pflash_cfi01.c".
Argh yes, thank you! >> header, "It does not support timings". 12 years later, we never >> had to model the device timings. Time to remove the unused timer, >> we can still add it back if required. >> >> Suggested-by: Laszlo Ersek <ler...@redhat.com> >> Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> >> --- >> Yes, I plan to model those timings later. Actually I have a series >> working, but I'd rather first >> 1/ refactor common code between the both CFI implementations, > > Good idea. > >> 2/ discuss on list whether or not use timings for the Virt flash. > > What would the timer buy us (specifically wrt. cfi01 / OVMF / ArmVirt)? > > Being faithful to actual hardware is always good... except when it runs > a significant risk of regressions. :) By that I don't mean "programming > errors"; I mean that guest code would now have to conform to various > timeouts, and that always makes me a bit concerned. I'm glat you feel concerned :) My goal is to model enough of the device to be able to run 'Capsule Based Firmware Updates' [*], but I haven't investigated much yet. Embedded firmware usually care about such timings. Anyway if this is implemented as a feature, it would be disabled by default for the Virt flash (I name the Virt flash the one used by the Virt X86/Aarch64 machines). > > For this patch, with the commit references fixed: > > Reviewed-by: Laszlo Ersek <ler...@redhat.com> Will do, thanks! > > Thanks, > Laszlo > >> --- >> hw/block/pflash_cfi01.c | 15 --------------- >> 1 file changed, 15 deletions(-) >> >> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c >> index 16dfae14b80..6dc04f156a7 100644 >> --- a/hw/block/pflash_cfi01.c >> +++ b/hw/block/pflash_cfi01.c >> @@ -42,7 +42,6 @@ >> #include "hw/block/flash.h" >> #include "sysemu/block-backend.h" >> #include "qapi/error.h" >> -#include "qemu/timer.h" >> #include "qemu/bitops.h" >> #include "qemu/host-utils.h" >> #include "qemu/log.h" >> @@ -86,7 +85,6 @@ struct PFlashCFI01 { >> uint8_t cfi_table[0x52]; >> uint64_t counter; >> unsigned int writeblock_size; >> - QEMUTimer *timer; >> MemoryRegion mem; >> char *name; >> void *storage; >> @@ -110,18 +108,6 @@ static const VMStateDescription vmstate_pflash = { >> } >> }; >> >> -static void pflash_timer (void *opaque) >> -{ >> - PFlashCFI01 *pfl = opaque; >> - >> - trace_pflash_timer_expired(pfl->cmd); >> - /* Reset flash */ >> - pfl->status ^= 0x80; >> - memory_region_rom_device_set_romd(&pfl->mem, true); >> - pfl->wcycle = 0; >> - pfl->cmd = 0; >> -} >> - >> /* Perform a CFI query based on the bank width of the flash. >> * If this code is called we know we have a device_width set for >> * this flash. >> @@ -771,7 +757,6 @@ static void pflash_cfi01_realize(DeviceState *dev, Error >> **errp) >> pfl->max_device_width = pfl->device_width; >> } >> >> - pfl->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, pflash_timer, pfl); >> pfl->wcycle = 0; >> pfl->cmd = 0; >> pfl->status = 0; >> >